Though (on the H9, at least)…with MIDI cc, or an expression pedal, you could dial the delay time to any precise delay time value in ms.

I set my delay times to my exp pedal a lot…and have full range of values.

This might be better for you..if it can be done on that pedal…since it sounds like you are trying to tap out something other than the actual song tempo. Unless your songs are at 20bpm…. Which I imagine would be excruciating 🙂