SUMMARY there's no smb4k flatpak on the kdeapps repos. would be nice to have.
Unfortunately, I don't know how to produce flatpaks. If someone could help out here, that would be great.
After trying to package Smb4K as flatpak, I have to admit that I give up. I was not able to make Smb4K's flatpak invoke the mount command. And, at the moment, I assume that the design of a flatpak won't allow that invocation. Sorry.