In my experience, I rushed a job and packed insulation right up against some old recessed cans. They started overheating within a day, and the homeowner called me back panicked. It was a wake-up call about following clearance rules. Always leave at least three inches of space around any heat-producing fixture. Your mileage may vary with different insulation types, but this is a basic safety step. Take this with a grain of salt, but I won't make that mistake again.
I was fixing a wall in a studio and used leftover batts instead of cellulose. The client said the noise drop was way bigger than expected. Do you think batts are underrated for sound control?