Notifications were delayed starting a few weeks ago, now seem OK (RN7)
A comment on what I think is a problem introduced a few weekly updates ago, which now seems to be fixed:
I use various time notifications on a Redmi Note 7 (lavender), e.g. Google Keep, and a calendar application (not Xiaomi's). When I initially bought the phone, with its stock global ROM, I had a lot of difficulty getting notifications immediately, the usual problems with autostart, battery optimisation, etc. xiaomi.eu was much better, and I was receiving timely notifications.
A few weeklies back I started noticing that notifications were delayed, mostly by 3 to 5 minutes I think (with autostart enabled, battery optimisation off). I didn't report this immediately as I hadn't installed the latest weekly. I've just installed the 27 January 21 weekly, and notifications seem to be back to normal. I haven't seen any reports of this (maybe I missed them?), so it seems that something went wrong, at least for RN7, and then got silently fixed.
Another point that I found a nuisance is that some updates disable some notification sounds, or change sounds. It's easy enough to re-enable sound, but at first I missed some events that mattered to me. (I have always "dirty-flashed" weekly updates on my rooted RN7, and never had a problem.)
This is intended as constructive comment; as always, thanks and congratulations to the developers for an excellent job.
Best wishes, pol098