i see things about the benefit of gr-meter allmost the same like you, especially in the nebula world. while on a real hardware box the needle shows you exactly what the vca is doing, nebula kind of guesses the action by comparing two envelopefollower, one before and one after the process.
so a reasonable implementation of a gr meter for nebula would actually be just one or two LEDs like on the D*x 160a. they just indicate if the signal hits the threshold. such indicators as well as a full meter are quite useful, not to tell how the comp is sounding, but to tell if it is working. of course one can and should hear this too while tweaking it. but imagin a chanelstrip with five or more plugins and you're hearing something's wrong. now the meter will be able to tell you quickly wether you'd have to search the fault within nebula or elswhere! thats what meters mainly are made for in my opinion, faster troubleshooting
That's a very interesting idea, brp. I might have to try to work up something based on that (can a skin have more than 2 meters? I can't remember anymore, has been a long while since I finished those skins heh).