Today I installed a new cartridge on my system, an Audio Technica AT33ML/OCC with Soundsmith ruby retip. I have never attempted VTA shimming on this or any turntable, so my perspective is what is. That said, inserting the shims went as easily as it could, and they look fine on the table. I inserted from the rear for convenience and the resulting gap at the front was no visual problem at all.
I continue to be surprised at how little shimming non-Rega carts need with the RB330. I used two of the thinnest (1/32") to level, and I think I will remove one or both to go a bit tail-down based on listening and reading.
Rega RP3, TTPSU, Groovetracer delrin, reference subplatter & counterweight, Lim double pulley
Shelter 501-II with Soundsmith Level II, Heed Quasar