Two screens, two home screens

A Fold is two phones in a trench coat, and it should not be made to wear one outfit.

What One UI does

Out of the box, Samsung mirrors your cover screen layout onto the inner display, so the same apps sit in the same order on a screen more than twice the size. On the Fold 7 and 8, Samsung also removed the grid options for the inner display from Settings, leaving Home Up in Good Lock as the way to get them back.

What Folio does instead

Each screen keeps its own layout. The cover gets a phone-sized grid. Unfolded gets two Home pages side by side, or one centred page with a dock bar in portrait.
The layout follows the room, not the model. Folio measures the window it has been given, so split screen, a flip, a tablet and a Fold each get something that fits rather than a stretched phone.
Half folded is handled. Sheets, menus and Home rows move off the crease, so nothing important sits in the fold.
Per-page icon size and labels, so the inner screen can hold more without everything shrinking.

If your cover screen still mirrors

That setting belongs to One UI, and it can stick after switching launchers. Open Android Settings, find the display or home screen section, and turn off cover screen mirroring. Folio then lays each screen out on its own.

Coming back from a change

Layout History, in Folio's beta features, saves your Home before big changes so you can go back to how it was. Turn it on in Settings before you start rearranging.