Yes, that mod will export the current room as one massive scene. You need to install it onto a specific version of Worldsplayer, 1922 I think. Then there should be a new button in the Options menu.
Here's the catch: you need to manually make changes to the RWX in a modeling program, the RWX exporter does not properly store materials etc. Everything will be insanely big and you'll need to tweak your distance clipping settings in the camera to even be able to work with it, since Worlds internally uses some stupidly massive integer numbers for it's math. The scale and position of PosableShapes is way off, and sometimes they just get skipped entirely so if you're trying to rip avatar models it can be a real pain in the ass.
But it is definitely possible, it's how I got my
Taistelugo 3D model (I have similar rigs for Nexialist's and Wirlaburla's avatars too), as well as how I rendered the
animated background on Kangworlds.net, which is a recreation of Jets GZ.