Thankfully -ates really a huge problem in Sketchmons, but though something could be done with a couple of them I guess. There are only three -atESpeed abusers all of which are Megas and the most threatening of them (Mega Pinsir) is still checked by some of what checks him in OU (Mega Meta, Zapdos, Rotom-W). In hindsight though, I guess Mega Pinsir could be suspected or banned seeing that things like Thundurus, Mega Diancie and Mega Aero get OHKOed by +2 ESpeed after SR, which is kind of sad.
I'll admit that Sylveon and Mega Alt are difficult to deal with however. There aren't any switchins to either of them with Boomburst (except for Sp. Def Mega Venu in the case of Mega Alt) and both can still use their defensive typings to be useful outside of hitting things. Specs Sylv can literally just spam Boomburst mindlessly seeing that stuff like Ferrothorn, Sp. Def Skarm and even Mega Aggron get 2HKOed. Heatran needs to watch for HP Ground and Sp. Def Mega Venu needs to watch for Psyshock. Sylveon is probably unhealthy. Mega Alt isn't as obvious imo, but its versality makes it hard to deal with. Mega Glalie and Mega Garde are fine.
I'll admit that Sylveon and Mega Alt are difficult to deal with however. There aren't any switchins to either of them with Boomburst (except for Sp. Def Mega Venu in the case of Mega Alt) and both can still use their defensive typings to be useful outside of hitting things. Specs Sylv can literally just spam Boomburst mindlessly seeing that stuff like Ferrothorn, Sp. Def Skarm and even Mega Aggron get 2HKOed. Heatran needs to watch for HP Ground and Sp. Def Mega Venu needs to watch for Psyshock. Sylveon is probably unhealthy. Mega Alt isn't as obvious imo, but its versality makes it hard to deal with. Mega Glalie and Mega Garde are fine.