While I don't deny BP's utility for the revenge kill, I feel like the two scenarios machamps stands in regards to a fairy is predicting the switch in, but knock off/dynamic or even stone edge would be just as good in terms of damage/utility (priority wouldnt matter in this case) despite resisted, or you're staying in to take out the fairy and trying to get a revenge kill with BP IF it's weak enough. If it's not weak enough machamp is swallowing one move at the fairy's disposal and I feel like you're better off just firing a nuke like stone edge or cause a confusion hax for a better opportunity. The priority is probably better off for a different member to make use of machamps wall breaking prowess and coverage(that you would gain from not using BP as well) unless you've designated machamp to be the sweeper himself.
Also to continue from my above post, it seems that machamp really benefits on paper more from AV as he can stomach crucial 2HKOs to either 3HKOs, or maintain enough HP to be a nuisance before he dies. Alternatively, using the careful spread with max HP/sp def. it basically mimics the AV benefits but you lose damage and some HP that you hope to regain through bulk ups, confusion hax, 2-3 turns of left overs which is probably feasible under sub/hax.
I personally have no experience with the bulk up sets (with leftovers) or even the bulk up/sub set(with leftovers) combined but has the lack of said coverage really deterred machamps wall breaking power? The one thing I noticed from damage calc was that while using adamant, you can probably afford to spend say 80 points or more to say sp. def to have some benefit without deterring his power to do over 50% HP to threats.
Feel free to correct any of this or if I missed out key benefits of certain sets, I just want to really see the benefits of certain sets before I make one on my DS lol. I feel like machamp should be seen as a mon of it's own, not really in conkeldurrs shadow, because I play him for the sake of dynamic punch utility and personal preference.