RGB defaults to 0-100% in 8-bit images
It appears that users do not expect GIMP to default to 0-100% range when picking a color and would rather prefer 0-255 integer. See this thread:
https://www.reddit.com/r/linux/comments/s0o69d/sorry_but_gimp_is_just_frustrating_to_use/
I think it does make sense to defalt to 0-255int in 8-bit RGB and 0-100% in other encodings. What do you think?