Thank you for your helpful replies! I've found the solution for converting RealFrac patterns into Integer ones in an older thread (cf. Rounding Float patterns - #3 by yaxu):
d1
$ spin (round <$> perlin*100)
$ note "b5" # "superpiano"
+ up "-7 -5 0 2 3 -5 -7 2 0 -5 3 2".
The round function was exactly what I was looking for, although I'm unsure how the operator <$> functions. Time to finally dig into how Tidal is implemented, I suppose:)