there's definitely interest indeed, the problem is it's very unclear how to do it. Decisions that must be done is:

- Bit width. Hardcoded, configurable via Cargo features, configurable via generics?
- Tick rate: Hardcoded, configurable via Cargo features, configurable via generics? Const generics? typenum? Just a frequency value? or a full NUM/DENOM fraction?
- Who gets to choose these settings? the HAL implementing the trait, or the driver using the trait? 
- Single global clock, or multiple clocks? If multiple clocks, can they have different settings?

Example 1: embassy-time: 
- bit width: hardcoded to u64, so it never overflows. (prioritizing convenience over efficiency)
- tick rate: configurable via cargo features. Some HALs choose it, some let the end user choose.
- Single global clock, so you can do `Instant::now()` from anywhere without having to pass around stuff.

Example 2: fugit
- bit width: configurable with generics
- tick rate: full NUM/DENOM fraction, configurable with const generics.
- Who chooses? the HAL implementation (I think the HAL can choose to be generic so the end user chooses? but either way the driver can't choose)
- Multiple clocks, each can have its own settings.

as you can see they're polar opposites.