I understand (from @Brian) that there is a problem with most plugins, notably VST, in that they are designed for a monolithic (single computer) architecture: the user interface is combined with the processing. This is not Roon’s architecture: Roon separates the user interface ( Roon Remote) from the processing including DSP (Roon Core) and the music play (Roon endpoint). Sure it is possible to put those three functions on the same computer, but they are still separate functions.
A plugin that combines user interface with processing is old-fashioned, fits the old PC mindset in the 90s but not today’s networked world. It somewhat fits the phone app model, although even there we have playback capability when the UI is not visible.
I’m particularly sensitive to this, having worked in the software industry for a long time, and having cleaned up such monolithic systems time and time again. A PC used to be a thing; now it is part of a distributed system; a very big change with lots of subtle implications for installation, discovery, power management, troubleshooting, security…