I use a 4” PVC halfpipe on the front of my chair (for most of my hanging angles), and an electrical timer. I think this makes a fairly safe environment for multi-tasking. It’s an adjustable height chair—I simply make it taller if the weight hits the ground.
I agree its hard to monitor hanging while multi-tasking. At least for me, if I get too much pain at the BTC angle, I simply switch to SO by shifting my butt in my chair. I’ve made significant gains with hanging, so at least for me it’s worked fine.
There is some pain with hanging—I think it makes it hard for me to do work that requires high levels of concentration. And when I’m really concentrating well, I worry I’m going to not pay enough attention to my hanging and tear something.
I think with more practice I’ll get better at doing this all safely—
Generally, the first 2 sets require more concentration, because I’m building up to reach fatigue. I do pay less attention with subsequent sets since generally I drop the weight after set #2, and the danger of an injury is much lower at this point since I’m doing less than my maximum weight.