I personally explicitly avoid parallel agents, since it creates too much cognitive debt, and sometimes an agent may need steering towards an architectally sane solution mid-work.

Totally agree, the more parallel agents you spawn the more the probability of you vibe coding rather than guide coding. There comes a point when my mind says just commit and move on, which I fight to not do it.

Same here. Reviewing gets harder too and multi tasking kills any kind of productivity if you need to review the code then.

My approach these days is to do one change at a time, until I can fully merge it with confidence.