Yes. I thought that was obvious, but perhaps not It's not called "USB pass-through" for nothing, the guest OS sees the actual device with whatever is on it. The pass-through works on a much lower level than a filesystem.
I'm honestly unsure if compressed VMDK can support split files at all. I know VirtualBox does not. For regular files, split VMDK (chopped up into 2GB-sized chunks) is an option, and it was invented exactly to work around the file size limitation.Upon export the VDI format converts to VMDK so compact no longer works.
That's something VirtualBox can't really help with, you need to talk to the Solaris guys. As far as I know, FAT32 is really the only FS supported more or less everywhere, but it has serious limitations. ExFAT is supported on most newer OS releases but not Solaris 11.If anyone knows of a single file system format that is supported under Solaris 11, Windows 7-10, and Linux 6 & 7. I'd like to hear from you. I have tried everything but am still haven't discovered any that are "supported".
At present I don't think there's any file system that supports 4GB+ files and works across Windows/Linux/Solaris, but I'm not a Solaris expert.