I was wondering if the problem was being caused by the use of this:
Mitsurugi_w_NoCD Utility.iso , assuming it is this https://www.arcade-projects.com/threads/mitsurugi-ws-cpsiii-nocd-utility-disk.16/
but from reading the thread that is to write an encrypted No CD image to simms using a superbios CD cart which would be swapped for a genuine No CD cart which isn't applicable here.
Tika the reason for this is because the Zulu SCSI is working, its emulating a scsi drive and since you have a 2I cart it lets you install 2I. Just reiterating what Kazuo said you shouldn't be able to get past the boot menu without that 7th simm, you would normally get a not enough memory error.
You actually need a CD cart to install with first unfortunately, if you check out the main thread there is recent discussion on updating carts to have a dual bios (CD/No CD), so you could install in CD mode then flip the switch and boom no cd.
Thanks for the reminder - I did see a post about making a cart essentially be dual boot with a microswitch - I'll explore this option as it may make things easier for now and in the future.