at moments when this is a problem, my butt is nowhere near the saddle. standing and hammering over dirt paths with unpredictable protruding rocks is the issue. it's not my body that is getting beat up, it's the bike. I went through this in another thread and several people came to the same conclusion: 32mm tires were not enough. 35 is an improvement but it's still severely lacking. 35mm tires at 35-40 psi is the only way I can ride this bike, standing up and being as dainty as possible over the rocks, otherwise I trash tires and rims. I rode BMX for 20 years. I can bunnyhop this bike up a foot-high ledge (which is not all that impressive), so I know how to be light on the bike. the tires are just too small for my riding style and terrain.

if what you're saying is that modifying this frame is absolutely impossible for any metalworker to pull it off, or at least at a cost that is reasonable considering the cost of the bike and my limited budget, I guess I am screwed until I win the lottery (which is also impossible because I don't throw away my money on that, just crap bikes that never suit my needs) so I can afford a bike that will hold up for my riding style.