Hi,
I noted that the shortest interval using FSRS 5 seems to be 7 minutes (this is at least what I ended up with adjusting the parameters and checking the intervals on a new card, hope I did not do something wrong).
Was curious if this was on purposes as personally I think a lower value is helpful for new cards.
I used 24.11rc1
From what I recall it has to do with the minimum computed stability, which imposes a limit on the shortest possible interval that can result.
IIRC it comes down to the minimum stability being 0.01 of a day which works out to a few minutes. This is then compounded, or adjusted, based on desired retention.
My current work around is that I do have a custom learning steps of 1s and 3m and letting the scheduler take control of the rest of the learning steps.
Reason being that FSRS cannot yet link short-term memory and long-term memory. It can also not yet link custom learning steps and the scheduling so that the scheduling cannot calculate learning steps based off your custom steps (yet). I hope this changes.
Thx for the feedback !