Actually that shouldn't be necessary and creates problems: .https://forum.elivelinux.org/t/disabling-network-manager-for-connman
Considering Elive E16 uses nm-manager and E24 uses connman, it's simply a matter of turning on/off one or the otrher when logging in to a different desktop manager.
So also considering that E24 is the "deviant" here, we only need a small script added to E24 startup that disables nm-manager and enables connman through systemmctl (after making sure that connman-gtk is installed)...... and of course the other way round when leaving E24. 
