That looks very promising, I didn't know CloneZilla was customizable.
They all are customizable !, talking about boot mangers, they all can have menus and run scripts, so all you have to do is make two scripts to create/clone and restore or boot from .
On all my devices i use/used EasyBCD to adjust the boot and replace the UEFI default one, now i use GRUB which is also customizable, and have very nice feature witch is boot from an ISO image on local disk !
My recovery flash is also support booting from ISO so i have multiple ISO on the flash where i can boot from any of them.
Fun fact : my Android mobile is rooted with Magisk and installed a module (there is two i think) that unlock the power of using the mobile as bootable USB ( in fact mine doesn't support USB boot, but only CD-ROM) ,in all cases i have few ISO's images on the mobile SDCARD include linux live CD, Acronis, MiniTool Partition.... and i can boot any PC from my USB connected mobile.
