Hi,
I installed the ‘gnome-next’ ISO of 25 april. No problem with the installation. I tried the following Gnome extensions for Gnome 40: BigSurStatusArea, block-caribou36, CoverflowAltTab, Dash to Dock (last version from github), Improvedosk, SensorPerception. No errors when they were installed but the ‘Improvedosk’ extension can’t display her own settings. I will test themes (Mojave and WhiteSur) that I found on gnome-look.org website. They were made for Gnome40 and gtk4.
Would it be possible to add the BigSurStatusArea extension with the others extensions availables in Gnome Manjaro ? That extension is great. Look here: Big Sur Status Area - GNOME Shell Extensions and here: Big Sur Status Area - GNOME Shell Extensions for informations. It looks like what is made in the last version of MacOSX (look here: macOS — Wikipédia). Note: the first link is the good.
Regards.