Qubes 4.3 , Standalones, No Grub, no boot

Thanks to the developers, for their excellent efforts. From what little I have used the 4.3 release candidate, I like it.

If I use my own recently downloaded Fedora 42 Workstation, (Not the Fedora 42 -full Template) then the live version boots, Installs and will restart.

Other ISO’s, like Pure, Ubuntu 24, on trying to start in the standalone give error message. No Grub. No Boot.

I have allocated drive 20 gb, max 30GB. with differerent efforts. 4, 8, 16 GB RAM.

I must have missed doing something in the correct order.
Maybe some new feature regarding handling of UEFI? Maybe Developers feel other Linux OS’s represent a Security Risk?

I can, I guess, put a Grub on standalone Qube, and install into it a link to what ISO I want to install

Computer is T480, I7, 32 GB RAM. 256GB SSD with freshly installed version of Qubes 4.3, latest release candidate. Nothing else on drive-- lots of space available on SSD.

Thanks for reading this.

I had already spent more than ten hours with this before posting, so I felt it was all right to see if someone knew the answer off the top of their head.

Problem is:
Initial RAM was not being correct in Settings for the newly cloned Qubes.

Solution is:
Going from blue Qube, upper right of screen.
Choose Stand Alone. Do not clone. Do not use Use Template.
On down, Advanced, in the next drop down inside Advanced. Set the initial RAM.

I actually do not know what the initial --minimum RAM - is. I just choose 8000 mb. Which is surely way too much.

Pure OS, Seems to function as StandAlone worked in Previous version of Qubes. 4.2.4

At one time in working with trying to get it working, I saw an error message. about Qrexc not –