Geez, I wish I followed this thread when it started…
You’re 5’8, you CUT down to 140 lbs, and still have 15% bf?! Dude, you’re doing something wrong here. I’m 5’8 and I was 150 lbs in college just being a normal guy who didn’t go to the gym (and clearly looked like I didn’t go to the gym!)
My two cents: Forget bulking or cutting, figure out what you need to train hard and maintain where you’re at. Then, add a SMALL surplus on days your body will likely make use of the additional nutrients (not on off days when you sit around doing nothing). Keep doing this for several months, and more than likely you will have added some quality lbm which will also have shifted your bf% in the process.
S