st martin diamonds, mankind codes, jungle riders and cyphrs do not have a bend and i've seen every one of them broken already. I don't think the bend is nearly the issue and much as thin tubing is. combine that with a poor design like elevating the downtube above the bb (quamen delta/cyphr/g7, suelo simple, mankind code) and it's going to fail, with or without a bent tube.
i use to do ankledeaths "b.i.t.d". Or if I were to attempt halfhikers ( I'm not there, but just questioning it) are you saying I wouldn't have a touch more room if i tried one on a frame like the flatware or strowler? that's the type of "clearance" i was speaking of.
I do see how a bent downtube could be weaker on street or ramp (friemuth style 4ft airs to land in nosepick) but I just don't see it on a straight flat machine.
I guess it's all just preference when all is said and done.