Hello, I am trying to dual boot cachyos and windows11, and the installer errored out saying that an external command failed. the bootloader i chose was systemmd(default). Here is the link to the log: https://termbin.com/9ity
for dualboot linux+windows GRUB would be my first choice 
also on this video
You are reusing Windows’s EFI partition, which is too small. Either resize the partition to have enough same to accomodate Linux’s EFI binaries, or refer to our wiki on manual partitioning for dual boot.
Ended up just getting rid of windows entirely - only wanted to keep it for gaming reasons but havent found a game i actually care about that doesn’t just work after following the video linked in the first reply.