OURA vs. Emfit QS (Or other non-wearable trackers) for HRV (Heart rate variability)

I’m interested in tracking my sleep and HRV. Mostly my HRV.

What I want to use it for:

  • Making month-long A-B-A-B experiments and seeing if some change improves my sleep
  • Seeing if I’m reaching overreaching or overtraining in bodybuilding.

I don’t want to buy Emfit or another non-wearable sleep tracker if it gets imprecise when sleeping with a partner. On the other hand, it seems more convenient than putting on a ring every night.

Is emfit as accurate as Oura?

Do you think Emfit QS is accurate enough for my use cases? Or is another non-wearable tracker more accurate than Emfit QS?