I think that the notify app has an option similar to what you're after. It sends a notification to your band that tells you your sleep time and some extra details. I don't know how well it works though. But it's worth a try.
I'm sure there is a good reason for no responses. Maybe try asking some active users directly. I know some have completed requests in the past.
P.S. I would offer myself but I've only recently learnt how to do it, and frankly I'm not very good at it. (And the laptop I was doing it on has broke)
I found this, but I haven't tried it yet. Stock by Enisalmis - Xiaomi • Amazfit Mi Band 5 | AmazFit, Zepp, Xiaomi, Haylou, Honor, Huawei Watch faces catalog
I doubt it'll be interactive like the original.
I managed to connect mine. I just paired it like when you first pair your device. I don't know if you need to be paired with mifit also.
I signed into zepp with my mi account, and it seemed to work fine.