why not add quantization in tick value (or fraction of line 1/4, 1/3, 1/2, 1/8…) (not only in line), in this way you can quantize 1/32, 1/64 of bar…
maybe you can write 0,25 in the quantize field to have a quantization of 1/4 of a line!
Quantize to less than a line
List of feature suggestions for Renoise
Quantise in samples
And for controllers/automation too!