The new, tiny corner block is permanently upgradable. As you can see in the following screenshot, it says you can upgrade from combat steel to combat steel. If you try upgrading that you just get the multi tool churning though charges.
Just taken another look and this seems to be the way ALL of the new block shapes behave, although the small one above is where I noticed it.
Thank will be checked, to upload a save u can also use a file hoster or google drive or something like that
Ah, very important note. Since all those new shapes are in a third atlas... something isn't meshing or setup right there.
