Thanks, I used your article with MATE 19.10 and it worked nicely.
I didn't try your applet but instead heavily customised the i3wm and i3bar configs to my liking, wouldn't go back to a non tiling window manager now.
I love tiling WMs but I do have one gripe (and it's not the fault of the WMs): Every "about" window for every program should have the name of the binary in it so we can call it from the command line. Text editor? You have to know it's gedit. Document Viewer? Evince (say, what?) Want to use a gui for file management on a one-off basis (it happens)? Nautilus wait Nemo no that's not it shit fire up firefox and DDG...