Would be something nice to have, and there is a reasoning behind this idea:

• My first thought was, since prefixes and suffixes do have weights, why wouldn't the other meta key/values? I understand it's probably weighted from the group weight but it would also be nice for them to have their own weights; which brings me to the next point, if not:
• Why would prefixes/suffixes have their own weight system if the other meta pairs are "group weighted"?

I initially thought about this when I had to set up a tab_prefix set of meta key/values, to have a separate set of prefixes from the chat ones; the "normal chat" prefixes have their own weights as seen below, yet the custom tab_prefixes don't.

I get that this specific setup is very linear and straightforward, but it would be much more useful in a more complex inheritance tree scenario.

This config based system was implemented as a bit of a compromise to allow for more custom selection rules.

https://github.com/lucko/LuckPerms/blob/6f90e545fc42afc9d9a2c06ef446b198c62a2ef6/bukkit/src/main/resources/config.yml#L436-L450

I'm not keen on adding further weights/priorities to the meta system, sorry.