Some plugins build for ppc macs, wont load on modern intelmac machines, but there is a nice solution to make them work. I hope it`ll be useful.
I tried this only in renoise 1.9.1 & leopard 10.5.2.
Just find renoise app in app folder, click right button on rns app and choose
See the box
open using rosetta? Check this box and close info window.
Start renoise and rescan your VST folders.
Any comments are welcome.