Bella is certainly very alive, but we do not yet have too many posting around here. We work on it all day, every day of the week.
As mentioned on our About page, the company consists of myself (based in Minneapolis), and my colleagues Oscar & Albert (based in Barcelona). You mention Maxwell, well they (Oscar & Albert) originally created Maxwell before taking it to Next Limit, and I was responsible for Maxwell’s Rhino, SketchUp, Cinema 4D, and SolidWorks plugins (among other things), from around 2006 thru 2017. Around then we decided to part ways with the company to create Bella.
So that is our cards on the table. This is what we love, and we wanted to do it in what we think is a better way (e.g. our licensing, our sales model, and the renderer itself).
Regarding SketchUp specifically, I take it you are aware of the current rudimentary plugin; it is just that — basically I wrote a script early on, to allow the others to use SketchUp to make models for their development purposes. Once we went live, various people asked, and so I polished it up and released it, to let people who wish to do so, to play with Bella & SketchUp. A proper SketchUp plugin will come after I finish some things on our Rhino plugin.
So that’s where things stand, and I will welcome any input you may have on what you would like to see, once the time comes for me to begin that proper SketchUp plugin.