Ask Elektron and pray some gods like Odin, Thor, etc…
Check this :
The Untold Truth About Octatrack Tempo
In Audio Editor ATTRIBUTES, it’s 0.04 increment resolution actually.
With Fn + arrows :
0.04
0.08
0.12
0.16
0.20
0.25
0.29
0.33
0.37
0.41
0.45
0.50
0.54
0.58
0.62
0.66
0.70
0.75
0.79
0.83
0.87
0.91
0.95