Abyss is sort of a medium-high population area, if you can find a good world I don't see why 3 hours is risky. I'd only do 3-4 hours if I do a farm run or something in-between botting sessions (anything legit, not botted). But try to break more than you bot, so 4-4.5 hours break, as well as the obligatory 7-8 hour sleep.
However my sweet spot is 1.5-2 hrs botted (varied) 2-3 hrs break (farm run in-between), no bans and I'm not budging from this strategy since it works so well for me. Yes some people say this is slow botting but slow & safe gets us further.
Also I highly recommend using the fairy ring/cw method for cosmics, it's a newer method and fewer people are botting that - worth a try!