I magnetized all of my walls and found that metal mesh paper organizers work perfectly. There is enough steel in the mesh that the walls will hold to them. Also depending on the organizer, you can get one where the shelves slide out so you can simple pull a shelf out that has all the walls magnitized to it and bring it right to the table. Not sure I can post the link but I bought 3 of these off Amazon for $20 each "Veesun Paper Letter Tray Organizer, Mesh Desk File Organizer with 3 Tier Shelf Sorter with Drawer,Black" They fit perfectly in a Kallax (Ikea) square and 90% of the walls fit on a shelf. Only a few of the tall walls don't and they sit on the top of the organizer. Any of the overlays fit perfectly in the drawer at the bottom.

Not with TST but the test file is close enough to the real tiles that any issues you're seeing in the test will roll over to the actual purchased models. I have an S1 Pro and I would encourage you to keep tinkering with it until you are happy. The S1 is great for its price but it doesn't always work perfect out of the box and sometimes its a bit finicky. As for if these tiles will be great value, they are far above anything else on the market for Gloomhaven and indeed worth it if you want an immersive experience.

I think it has to do with Cura's slicing algorithm glitching. I've run into this issue a few times on the 1.5 cave walls or walls that have a lot of vertices. I kept Cura 5.0 installed and any models that have failed to slice in 5.1 have had no problem slicing in 5.0 so I think Cura changed something in their update.