The question is old, I saw it on the forums for Fedora Silverblue 30, but unfortunately there was no clear answer. Also a lot of time has already passed since that moment.
How I can install Midnight Commander in Silbverblue 35 beta? In Flatpak repositories I can’t find it (flatpak search midnight)/(flatpak search mc). Is it advisable to interfere the Flatpak-installations with the rpm-ostree-installation?