Would be a nice option to filter and only show M+ groups that would give a raider.io score upgrade if complted in time.

Ah, that's too bad

Would love to have this as well. However, addons cannot read the group text and description, because both are protected strings. Hence, there is no information about the key level of a group and the possible rating upgrade if in time. So this is not possible.

The only information I can provide is listed in section Player Info of the Keywords page. Have a look there.

I am currently working with a Weak Aura that shows affix rating and highest keys.