Bearing wear and low RPM high/load operation.
 

Looking at most manufacturer's BSFC maps, they tend to go from ~1,000rpm and up at little to full load. If they're testing these engines at WOT/1,000rpm, would it be reasonable to assume that those conditions wouldn't induce significantly more bearing wear?

Sounds reasonable to me. As long as the oil film maintains integrity it oughtta work. And why wouldn't it?

Although (and I'm not sure if this applies to newer engines or not) some components are splash lubricated and they could possibly suffer from low rpm/high load ops. I guess I'm thinking of lifters, but lots of the new stuff has roller lifters so maybe it's a non-issue on them.

You're right, I almost forgot about OHV engines. I don't think that would be as much of an issue w/ OHC unless oil pressure goes to crap for some reason.

Since you originally inquired about bearings only, I'd say they'd be fine. Cuz, think of the old Poppin' John Deeres- a really low rpm, high-torque demand situation if there ever was one. And they held up.

As long as there's no lugging or detonating...