Is it remotely profitable to farm all over act 5?

Like clear whole maps or something?

Specific areas yes. No advantage or benefit to clearing entire act. When farming you should really be targeting champion packs and skipping everything else.

World Stone Levels
Pindle
Nith
Shenk
Icy Cellar
Baal

Too lazy to check but I think thresh socket is a decent farming spot, especially for barb

if u want to lazily tele through a5 or even run and just kill all boss packs its not a bad mf strat. worse than targeted bosses, but not bad.

white mobs can be annoying tho, especially the tele dudes in the start of the act. but theres some high density areas u could do well in.

Really, just farming Worldstone Keep over and over will net you HRs, Elite Uniques, Sets and Rares consistently. I've had the best luck farming wise with WSK over the years.