The ability of Apple Watches to detect and accurately measure low heart rates

Specifically, I am interested in whether these devices can reliably detect heart rates below 40 beats per minute, especially during rest or sleep.

For reference, Huawei has officially stated that their wearables do not guarantee

accuracy below 37 bpm, and their measurement error range is ±10 bpm.

Based on this, I would appreciate clarification on the following points:

1.           What is the minimum heart rate that Apple smartwatches can detect and display?

2.           Are values in the range of 30–32 bpm supported and considered accurate?

3.           What is the expected margin of error when measuring heart rate at rest or during sleep?

4.           Do the devices apply any filtering algorithms that suppress or ignore very low readings?

5.           Does sensor sensitivity vary depending on the mode (e.g., sleep tracking, workout, manual measurement)?

[Re-Titled by Moderator]

Original Title: the ability of Apple smartwatches to detect and accurately measure low heart rates