You could have EndeavourOS in UEFI as well. It will be necessary to reorganise your partition scheme. First by security listen the magic Ball from @joekamprad and backup your sda11 142.89 GiB or don’t touch it or resize it. I put You below a scheme that will work for UEFI.
sda1 FAT32 Mount : /Boot/EFI Flag : boot, esp 550MB (550Mo is what The author of gdisk suggests which is 524,52Mio or 0,51Gio)
sda2 EXT4 Mount : / Flag : nothing 27.94Gio
(means 30Go for your system EndeavourOS)
sda3 EXT4 Mount : /home Flag : nothing 273,57Gio
(means 293,74Go for your Personnal Data, the value would be near from that maybe not exatly, extend the size at maximum until the start of your Swap)
To make it easier on Gparted :
1/ delete sda1
2/ delete sda2
3/ You will obtain an empty unknown space
Use it to create the partition scheme I show You up.
4/ install EndeavourOS on sda2 /
5/ After install, You could also access to your sda11 data to bring them to your new sda3 /home
6/ After this clean install, you could do what You want with the space from these partitions placed after your Swap which would be sda4.