Can someone confirm me that the UV on the UProceduralMeshComponent are 32 bits?

[Sam_Swain]

This is true. Unfortunately, on platforms that support them, the scene proxy for the UProceduralMeshComponent passes them in as half precision Float16 values, losing accuracy. This can’t be overridden without engine changes (or copying and customising the proxy used and overriding the CreateSceneProxy method of the UPMC).