I’ve tried the latest test ISO from Index of /qubes/iso/ :
Qubes-20210424-x86_64.iso
24-Apr-2021 04:53
5408555008
At least it starts the installer on my NUC10i3FNK ( NUC10i3FNB main board).
Maybe I’ll try a fresh install later today or tomorrow.
So it was fixed in development in version 4.1 already in io-apic issues on install boot for 4.1 NUC10i5FNH #6372.
Hans