I’m about to post one more bug in installation program: auto generated partitions may lead to error installing Linux firmware - you need to plan separate /boot/efi partition when you use dual boot (I use at least 3 OS booting ) and replace /boot/efi mount with your own partition prepared for use as efi . At least I have 3 efi partitions currently and it works. The bug, when triggered, is fatal - installation program allows only exit.
If this really matters I could upload the photo of partitioning triggering the bug. The problem, though, is easy - on /boot/efi I’ve Microsoft files & the space is not enough to store everything that Qubes OS wants to be there. Workaround is also simple - prepare the partition for /boot/efi as unformated and replace mount point after auto generating partitions.