This is possible in Nim using the "soft real-time" GC with "GC_step Mode" see https://nim-lang.org/docs/gc.html. You can even tell the GC how much time it can pause.

But Nim also has a new deterministic GC, that has been available since 2020 and will be the default in a future version, see: https://nim-lang.org/blog/2020/10/15/introduction-to-arc-orc...

In fact, I see many similarities between Nelua and Nim.