I don't necessarily want to return to the days when overtuned Items ruled the metagame. I value our ability to buff weaker Pokemon and playstyles by designing new Items, and I don't want to deter this aspect of our balancing process by setting damage-boosting Items too close to the top of the metagame. However, I also don't think that simply having many Items to choose from would help the send-out issue I described, as this only helps a player's catch-up attempts after the snowballing has already started.
Ideally, damage-boosting Items would be consistently useful. As I laid out above, I believe that there is no such Item that currently meets this standard. These Items need not overcentralize the metagame to achieve the desired effect; many damage boosters can reach this level with minor adjustments. Life Orb is the easiest to change, as a reversion of the proposed nerf would make the Item usable but not overpowered, as 2 HP recoil is still significant enough to sway the foe's KO thresholds and break the user's Endure.
As another example, I think that the sweetspot for Expert Belt is +2 BAP to all supereffective attacks. This is a worthwhile effect, but not strong enough to dissuade a player from using other Items. If a player sees their Pokemon's STAB moves will be particularly useful, they can pick a Silk Scarf-type Item. If the holder's survivability against a specific foe is paramount to success, they might want a type-resist Berry, Absorb Bulb, Focus Band, or another such Item. If the Pokemon has interesting Ability tech, Leftovers / Black Sludge, Toxic / Flame Orb, or one of the new Signature Items may be an appealing option. If a Pokemon doesn't need any extra help to reach a threatening DPR, a defensive Item would be viable. If an opponent has picked a powerful, yet exploitable, Item, a blatant counterpick choice has merit, such as Cleanse Tag / Shed Shell vs Binding Band or Protective Pads vs Rocky Helmet. If a Pokemon relies on recoil attacks to stay relevant or crumples to passive damage, Cleanse Tag again comes to mind. Finally, if a player wants a higher general damage output, they can accept the drawbacks of Life Orb or Choice Band / Specs.
Regardless, any Pokemon with a decent movepool could always fall back on Expert Belt if the act of committing to a more specialized Item would carry too much risk. While first send-out will always be challenging, "safe" Item choices like this help reduce an unnecessary degree of danger that is imposed by the new versions of damage-boosting Items. I agree that a repetitive metagame is undesirable, but I don't believe that forcing players to gamble on suboptimal choices is a good alternative.
I will admit that I have overlooked Choice Scarf so far. The Speed boost should be very helpful for Pokemon that don't rely on Items to meet important damage thresholds, and the fact that Scarf only removes one substitution is very nice compared to the other Choice Items. Personally, though, I would prefer to see the accuracy boost return to compensate for match-ups in which the Speed boost doesn't matter. Otherwise, the user is occasionally burdened by the loss of a substitution with no benefit from the Item.
Nevertheless, my focus was on Choice Items as damage boosters. I won't deny these Items' strength when ordering second, but it's important to consider the fact that you must order first eventually, and I don't believe the new Choice Items provide enough power to offset their weaknesses in this inevitable situation. One substitutution is vastly appreciated against Counter and Mirror Coat, but this is ultimately useful for only a small pool of match-ups; contrast this to the old Choice Items, which helped against a wider variety of match-ups by effectively adding four substitutions for Torment, Encore, Disable, and Imprison. Moreover, the old Choice Items also traditionally added between 4.5 and 6 BAP to all attacks, which allowed weaker holders to punch through foes too bulky to otherwise handle, and they could be used with Trick / Switcheroo to pose a potent, though gimmicky, threat to any foe.
For the record:
I was aware of the weaknesses you pointed out, but I did not view them as marks against Heavy-Duty Boots's usability. Instead, I thought they transformed the role of entry hazards from a tool for switch pressure and chip damage to a preemptive form of Item control. Because this freed players from incorporating traditional hazard removal into their teams, I considered it a net neutral value.
I think that Heavy-Duty Boots's on-cartridge effect is a good-enough chassis, and that we could make the Item usable and distinctly different in role from the new Cleanse Tag by tacking on a unique secondary effect. First, we could add a +2 / +3 BAP modifier to kicking moves to Heavy-Duty Boots's old effect. When taken alongside HDB's immunity to Sticky Web, this would establish the Item as an offensive variant of the new Cleanse Tag; however, I am aware that such a decision might not be favored in the current metagame. Another option would be to extend Heavy-Duty Boots's ability to protect its user's switches by adding an immunity to phazing effects. Any player looking to limit their opponent's ability to chicken-dance out of a bad match-ups would certainly find this effect useful. Finally, we could lean into the Item's nullification of Sticky Web's Speed drop by making the holder immune to all Speed-lowering effects. This would be invaluable in match-ups that could be swung by Speed control and D/E moves.
I guess I can understand that reasoning. I just worry that the Focus Sash user's opponent will find more value in the Item than the user tself.
10 Energy is much better than 6 EN, but 15 Energy is a steal when compared to the Energy and action commitment of removing and setting even a single move affected by Court Change. I would really prefer this move to cost a minimum of 12 EN, as it seems counterintuitive for a Pokemon to spend less energy reflecting an entry hazard than it would spend setting the hazard itself.
Except when used in the manner I mentioned before, Encore is primarily used as a playmaker. It briefly slows the pace of a match-up, but follows that action with a powerful punish or an elegant example of switch-play. If used smartly in this way, the Encore user can gain a substantial advantage in future rounds, helping to decide matches more quickly. I understand that prolonging our battles is a very valid concern, but Encore doesn't degenerate a match's speed to a concerning degree, especially when it now overrides only the following action. This change would only allow Encore users with good Speed tiers and/or Prankster to use the move to the same effect as slower Pokemon.
Honestly, I assumed the ability to choose a version to use was a deliberate, premeditated decision, as it reminded me of the nuances that ASB added to moves. Regardless, I would be very interested to see how a move with such a new combo type would work. I don't know if Shell-Side Arm would be the best test subject, though, as it has signature move distribution and is overshadowed by Poison Jab + Giga Impact and double Sludge (Bomb / Wave) combos.
I think Binding Band was fine at +4 BAP, as it was easily counterpicked and it locked its user into using attacks with a final BAP of 8. +2 BAP is much better than +0, though. Also, I like the new Grip Claw; previously, it was just a slower version of Binding Band, but this effect seems useful and unique.