It limits you to 10 editable things at once and I think caps the number of components you can have. I haven't found either of these very restrictive to my use cases as a home user/hobbiest. I hope the personal portion isn't going away, will have to deal with migrating everything and learning new workflows 😭
You can click export and save F3D file locally. Then you can delete it from the cloud and open a different file from your PC. I have dozens of the designs saved locally.
You can also mark designs as ready-only and they no longer count, so this limit is really 10 concurrently editable designs. I just keep everything read-only unless I'm actively working on it.
It works great for me. You push one button to make something read-only or not. There are very few functions that I care about that are blocked. I use it for design and even CAM on a CNC router.