I'm still using wmaker starting from late 90s (also had couple minor contributions)
> 1. There is practically no RandR support.
It is awkwardly implemented yes, as internally wmaker will restart, although changing resolution works for me most of the time. Wmaker doesn't identify monitors, it talk with xlib to get the layout when new display is detected or removed.
As for double dock - never have double dock issue. Sometimes I ended up with lossing it's configuration, especially in a cases when resolution set for the display is too low. That might happen when no display is detected/connected, then resolution is set to 64x64 pixels by X.
> 2. While there is EWMH support, […]
It's partially implemented, and indeed it lacks of handling self-managed application. Some apps are working fine (AFAIRC GTK3 based) and some don't (steam client), but in general for those which are not cooperate modifier key can be used to move such window around and keyboard shortcuts (which I'm mostly using anyway) to resize. Or to force window to use wmaker decorations as you mentioned.
This issue I've tried to solve couple of years ago[1], found culprit, but I've failed to do so. I've also spend a large chunk of time to compare it with PekWM, where those things are working as intended, but stuck on event handling.
As for composition. You might consider to use standalone one (xcompmgr, compton, picom, etc) just to get the effects.
[1] https://github.com/window-maker/wmaker/issues/20
> 1. There is practically no RandR support.
It is awkwardly implemented yes, as internally wmaker will restart, although changing resolution works for me most of the time. Wmaker doesn't identify monitors, it talk with xlib to get the layout when new display is detected or removed.
As for double dock - never have double dock issue. Sometimes I ended up with lossing it's configuration, especially in a cases when resolution set for the display is too low. That might happen when no display is detected/connected, then resolution is set to 64x64 pixels by X.
> 2. While there is EWMH support, […]
It's partially implemented, and indeed it lacks of handling self-managed application. Some apps are working fine (AFAIRC GTK3 based) and some don't (steam client), but in general for those which are not cooperate modifier key can be used to move such window around and keyboard shortcuts (which I'm mostly using anyway) to resize. Or to force window to use wmaker decorations as you mentioned.
This issue I've tried to solve couple of years ago[1], found culprit, but I've failed to do so. I've also spend a large chunk of time to compare it with PekWM, where those things are working as intended, but stuck on event handling.
As for composition. You might consider to use standalone one (xcompmgr, compton, picom, etc) just to get the effects.
[1] https://github.com/window-maker/wmaker/issues/20