After figuring out the transparency of Fluxbox, I was able to turn off Compton...
Booting now with the Liquorix 3.7.0-9 kernel and Fluxbox, I am down to an eve 100 MiB on boot and now claim Fluxbox as my default WM
Now onto figuring out the Slit mess, if I am reading it correctly it is somewhat akin to Conky
It's a dock. Not sure exactly how it works, but I have always had it center top and out of the way. I thought you was using it already, didn't know it was specific to fluxbox.
Feeling really stupid right know!
I've been using fluxbox with Ubuntu for a couple of years. It's small and quick. When I downloaded #!, I tried OB then returned back to FB. Just more familiar with it I guess. With Vsido, I used XCFE for awhile then switched back to FB. I THOUGHT you were using the slit to anchor Conky to the top! DUH Not in XFCE.
The best way I can describe the slit is that it is a relocatable dock that you can fasten Conky or whatever you want to it. I have Conky and bbrun fastened to it at the moment. I loved your Conky just the way it was but I added the date and time to the end of it. I used the slit to move it back up and center were you had it originally in XFCE.
Hope that helps.