How to blend a texture on a specific UDIM tile?

Hello. I have a character that uses UDIM textures for the skin material. I’d like to add makeup and tattoo overlays, but am having trouble with the UDIM stuff.

When I try to blend a texture using a mask texture and Lerp, it’s applying that lerped texture to every UDIM tile (i.e. placing a tattoo texture on arms, legs, torso, face, etc.).

How can I add a makeup or tattoo texture to a specific UDIM tile?

Have you found a solution to this?