When using the weekly graphical KDE Plasma Open-RC image, the graphical installer says the disk uses EFI and GPT, yet when choosing to erase the disk the review screen at the end states that it will create an MSDOS partition table on the selected disk. Booting into the system post install confirms that it was formatted with a MSDOS partition table.
I'm not sure this counts as a bug. Calamares just chooses what's a safe/sane/dumb default, regardless of a system's capabilities and existing settings.
To get to choose the partition table type one wishes, one should select 'Manual partitioning', where the options for either GPT or DOS partition schema exist.
I do agree with you though that Calamares should respect the existing schema, perhaps you could open an upstream feature request (https://github.com/calamares/calamares)?
Ok, I didn't know if this was an Artix issue or a Calamares issue. If my memory isn't bad the stable Artix ISO's version of Calamares did respect the default partition table. Something probably changed/broke during the time difference. I'll make a report on the upstream when I get the chance, thanks.
EFI requires a 32 bit VFAT in the efi partition, FWIW
https://wiki.archlinux.org/title/EFI_system_partition
It is part of the amazing UEFI specification.
Also
https://unix.stackexchange.com/questions/289389/what-are-the-differences-between-the-various-partition-tables
Thanks for the supplementary info mrbrklyn. I actually did not know there were that many partition tables. I do want to confirm though that nous was right and that this was indeed a Calamares issue. I went with the stable Artix ISO and Calamares correctly formatted the drive with a GPT partition table. I'll mark this as solved since this isn't an Artix issue.