No idea

I might look into a better solution for the REI hiding, though I do want to point out Platinum does not have a tool & armor set.
If Star Platinum gear is being hidden by this, then that is a bug, and will be fixed.

Well, I can use kubejs worldgen events to circumvent this. But for now, this technically isnt a bug so ill close it

Is platinum ore generation disabled? When disabled all Platinum items from MM are automatically hidden in REI, since they cannot be obtained normally anymore

yes it is, although I want the block to be shown

as well as the armor. I disabled the world gen so that I can use other ores