World partition, tiled landscape, materials and masks

Hello there!

Im looking into converting some old projects (read: completly remaking them ) in UE5 and i am planning to use world partition.

I have a 40x40km landscape that used to be tiled up in world composition before and each landscape tile has its own unique mask for the material to use. (and its own material instance).

Is there any smart way of doing this in world partition? i dont know if i am blind, but i cant find a separate material slot for each grid or am i constrained to use a extreme resolution texture for the entire world partition as a single mask.

also a suggestion: can we PLEASE keep the filenames of the original tile data somewhere as reference ex: XXXXMAP_X0_Y0.r16 i would love to keep some reference of the X and Y number of the tile if possible.