Bubble Cloud Widgets work well with the built in One UI launcher!
The stock launcher handles the front screen home screens separately from the home screen pages in the inside. So you can place a different Bubble Cloud widget on the front of the phone and another one in the inside (unfolded) home screen of the phone. It makes sense, since you will probably use a different set of apps in folded and unfolded modes. (Note: the non-premium version of Bubble Clouds only lets you place one app widget and one bookmark widget, but you can move app bubbles into the bookmark widget)
Slightly less happy news
I also tested Nova Launcher. It doesn’t yet work, since they attempt to reshape the same home screen pages to these wildly different screen shapes. You need a launcher that is prepared to handle the front screen home screens separately from the inside.
Nova Launcher cannot yet do this. Maybe they will be able to update to work well with foldables in the future. The current version 6.2.18 does not yet.