I've noticed that heavy zercher lifts are quite a rarity. Why is that? I know about the forearms thing, but it really isn't that bad. And sure, an odd lift like that doesn't exactly cross everyone's mind, but I'm sure that some strong dudes to do 500+. BTW, zercher lifts are from the floor, and zercher squats are from a rack (at least how I see it).
I recently did 380 pounds on Zercher squat (not hitting parallel but barbell was hitting thighs). I use just a very small padding to avoid getting bruises. The only hard part is to keep lower back flat. Goal is to get a 666 pounds+ Zercher squat in the future.
Haven't tried the Zercher lift yet but am going to.
But seriously, that has never been a problem with me. In all fairness, when I first started doing them, my forearms were so bruised that I'm surprised that someone didn't call child protective services on my parents. But I adapted and I never get bruises like that anymore. The weight seems to be supported by my upper forearms instead of sitting in that gap between the forearm and the bicep (which really would probably be a terrible idea). I've gone up to 320x5 on them before with no padding or issues. I honestly think that this exercise isn't as unforgiving as people think it is. This is all just my experience BTW; I realize that you may have a different predisposition as far as your tendon's tolerance is concerned. YMMV, to each his own, blah, blah, blah...