I do not give up on my openbox. I use it with LxQt. Now there is a Labwc, similar to openbox. It uses its XML spec for config and is similar. But I am still on X until all issues are resolved. Can I use openbox on KDE now? It used to be possible, I can choose WM in LxQt. Back then every WM had a --replace option.

IceWM got some nice updates in the last few years. I preferred it over Openbox and Fluxbox.