I was referring to samples that one specifically creates on their own – these used to be able to be added to BFD2 paths and you could load kit pieces with your own sounds.
I tend to use AU, so the VST problem hasn’t hit me that hard (…yet!)
However with respect to your VST3 question – I found a thread about that topic on this forum which mentions a couple of workarounds – I believe running under Rosetta is one of them, but there might be something useful for you in that conversation.