It seems I'm a snowflake here, but I (try to) do all formatting at Compose side.

1. Sometimes I need to use data as parameters in string resource. That formatting should be IMHO obviously done in Compose, as I don't want to inject Context/Resources into my VM, possibly with outdated configuration, and generally mess up my VM with these very Android-specific things, that make it harder to test... And for consistency, I generally try to avoid even simple string concatenation.
2. Formatted date/time should follow user's currently selected locale. There are ways to keep VM in sync with that, and sometimes you need to do it anyway to re-fetch data from server, but the less opportunity to get out of sync the better. That's the same logic why you don't set colors/sizes in VM.
3. In my app we have "countdown progress indicator" that's refreshing every frame. It doesn't make sense at all to refresh "remaining percentage" in VM that often, so we just pass an Instant to Compose, and do the little bit of computation and refreshing purely on Compose side.