I’m not able to install EndeavourOS with systemd-boot as dualboot on my system.
The grub installation works without any issues (from past installation tests).
Before you started the install, your EFI partition only had 3.2M free. Conservatively, you should budget 300M per kernel you install. It could be a lot less than that depending on what drivers you need though.
Thanks for the really quick answers!
I found the reason for the error:
My EFI partition is 500MB in size, so I assumed this should be okay. But I found out only 100MB of it was formatted.
I formatted the partition, now it’s 500M and the installation worked without issues.
I have to install the Windows boot loader again though. visible pain
Some time ago I resized the 100MB Windows EFI partition to 500MB using GParted, I assumed that the filesystem would also be resized and didn’t check again.