When using the Cockpit-based storage flow, it gets pretty weird if you want to do a complete custom setup.

You click "Modify storage" and go into cockpit-storage. You wipe all existing partitions. OK. Now you create the necessary partitions for your layout - say, a /boot , a /boot/efi , and a root partition. Cockpit prompts you to enter mount points for each of these, so of course, you enter them. It shows them all in its summary display when you're done.

Then you click "Return to installation" and return to the first page of the installer. But it still has "Erase data and install" selected, which feels weird given that you just created a bunch of partitions and assigned mount points to them.

If you go to "Mount point assignment", none of the mount points you set in Cockpit are respected. You have to set them all again here for them to actually be used.