Hey Jim,
Yeah, of course all the Apple made applications like Logic and Garageband use Apple's own AU format exclusively.
But there are still loads of apps Like Cubase for Mac that don't use AU and are VST only.

So although a lot people do think that Macs use AU only, the fact is that there are still a lot of Mac programs that do host VST's.
BIAB 2018 for Mac being one of them. smile

Hopefully I understood what you were asking. blush

- Jay

MacPro 5,1/12 core@3.46GHz -- OS X 10.14.6 -- ATI 7970 -- 32 Gig RAM -- Crucial 500GB OS SSD -- Samsung EVO 1TB Audio/Sample SSD -- BIAB 2023 -- Logic Pro X -- Cubase Elements 11 -- Too many plugins