Hey! Thanks for grabbing MiniMeters!
By "scale" are you referring to adding markers for different dB levels? The Spectrum Analyzer already has frequency lines in the settings. I plan to add something like that to the Spectrogram in the future but I am currently in the process of rewriting that meter to be more detailed in the coming update 0.8.0 so I won't be adding frequency lines to that (or some alternative way of telling the frequency) until after that is in!
I am not opposed to VU although that does require a different algorithm so I have no ETA on when I would add that. K-Metering and RMS is a viable option. I will look into adding them but I do intend to keep MiniMeters minimal and limiting the number of options as feature creep is a concern of mine.