I don't know the whole story, but I have read that U4T stems inside Cherry housings do conflict with GMK keycaps.
I don't know if that applies to regular U4T Boba switches in North-facing LEDs, but there can be issues when putting them stems inside Cherry MX housings.
https://domyessay.onl/ (https://domyessay.onl/)I have a board with switches facing the wrong way, so I used ART BOX switches, which are supposedly immune to the issue.