I noticed some of the adapter models for the 4-in-1 PTFE adapter from Bambu Lab was for the adapter from the A1 which doesnt have the small mounting tab sticking up (used to mount adapter to the P1P frame). Problem is when trying to mount to the P1S and X1C there's no provision for the tab to sit flush because of the enclosure so you have to let it hang. As much as that is fine, I wanted it mounted. I remixed mkd's mount adding a cut out for the tab and trimmed it a little to use less material.
All you have to do is replace the short screw(s) already there with the slightly longer one that comes in the bag marked “For Spool Holder." There's provisions to replace both screws if you have an extra longer one, but you can get away with only using 1 if thats all you have. Then the adapter just snaps right in.