Best Apple Watch alternative with best Athlytic compatibility

So, over the last couple of days I have fallen in love with Athlytic - it is the perfect balance of nerd and simple for my taste, and it gives me just enough insights to keep me motivated on my fitness journey. I have also, over the past couple of years, slowly fallen out of love with the Apple watch. I still like the hardware, but a bit of variety on my wrist would be nice, plus not having to charge the damn thing every day would be a bonus.

I would, in short, love to go back to wearing a (preferably) screen-less fitness band and a mechanical watch, but would also settle for a third party watch (e.g. Garmin) with a longer battery life.

My question to you guys in this subreddit is the following: which fitness bands and/or watches do you know of, that would sync all relevant data to Apple Health that would still let me take advantage of Athlytic? Specifically HRV, resting HR, wrist temp, SpO2, respiration rate, sleep (time is OK, cycles would be brilliant). Also doable are third party sync solutions, if those can also work.

Suggestions and experiences welcome and appreciated!

P.S. I know this is not directly related to Athlytic, but my focus here is to get an alternative hardware that would let me keep using Athlytic