Yep, its works with 4GB VRAM as you write. Many thanks for you comment, may its helps for forum colleagues. And as its can play nice with 4GB, its can play nice with 6GB, 8GB…
Manual AI mask (selection, area) with 4GB VRAM works fine even starts form PL 9.0 and all afterwards. Just need to know, what is the limit(s) for the ‘play nice’. As ‘Pre-defined AI masks’ is definitely a heavy VRAM user, its a limit for 4GB.
I write a post a while back about that (4GB).
I do this with AMD 4GB, may with nVidia even better.