The endianness being the same does not mean data structures are compatible. There are many, many more details about data structure layout that vary between arch

The endianness being the same does not mean data structures are compatible. There are many, many more details about data structure layout that vary between architectures (and even compilers of the same architecture, especially once you delve outside of C). VST2 is probably doable - what I use to run Windows VST2s on Linux is something similar with an out of process wrapper - but I can see VST3 with its C++ API being a major, major pain in the ass. And even then there are downsides. Running plug-ins out of process has significant context switching overhead. It's fine for one or two or half a dozen, but compare running 50 plug-ins in process and out of process and you'll notice a massive performance difference. You can fight that with larger buffer sizes, but that adds latency.