Yes, I like it a lot! Though I most often use Amethyst in split-screen - because it feels a little unnaturally wide when standalone ^^;

But it also means there is more text I can read.

It'd be nice if there was a layout with the tabs stacked on the side instead of at the bottom - or like a compose/reply window just sliding out from the side instead of taking up the entire screen.

If you need anything tested with a foldable, just ping me, I'll happily send you screenshots and stuff with a Pixel Fold. ^^