Thinking about the Recaps and their relationship to House Mercere and magi of other houses today. I’m torn.
On the one hand I really like the mixed politics that come from having non-gifted redcaps as equals to magi. It adds a turbulence to the lives of wizards, which is a good potential hook. It also enables players to have a more options in the setting for companions (which is mostly how non-gifted redcaps are played).
On the other hand I dislike that what is essentially a mundane being treated as a magus. They’re not, everyone knows this, and it’s only an old in-setting tradition that keeps it so. Given the other social castes of the era I think most magi would attempt to treat them as equals in name only. A redcap is not even close to a gifted magus.
My preference is to remove the Magus status from redcap character. Sure, they can be messengers protected by House Mercere and still have all the boons, but remove the pretense. This would be an upset to the Ars Magica setting, but one which I think would streamline the setting.