They reckon you should put your laptop through a full discharge > charge cycle about once a month for battery health, so I used mine until it went to sleep. But when I plugged it back in (and used it while charging) things seemed a bit funny. The keyboard was not lit (with these modern macs they are always lit when booted up) and the waking-from-sleep-progress-bar was still visible (but with mangled multi-coloured pixels) mid-desktop. So I decided on a reboot. That remedied those two problems but then I discovered logging in with fingerprint no longer worked. My fingerprints had been wiped. That didn't happen last time so I'm hoping it's a one-off. I've updated Monterrey since the last full charge cycle so maybe the update's got a bug.