You cannot even start the workbench by only relying on what's in ROM (note that at least "LoadWB" is disk-based), so I wonder why this is a useful criterion.
I know that but I have a floppy that start an extremely minimalistic workbench and includes a DOS script as an install option. I'd love to be able to start that script without rely on IconX or Execute to be present, that way I can be sure it'll start no matter what device or floppy you boot from... however the shell need to be in full screen and I don't want to force the user to manually do that.
Just looking into what options I have.
1) Ignore and accept that it'll fail in the cases where user boot from a different floppy.
2) Put IconX and Execute on the floppy, however if not in the same device (say they use DF1) it'll still fail.
3) Rely solely on ROM based alternatives (doesn't seem to be possible)
4) Rely ROM based alternative in combination with 3rd party software such as CLIwindow.