Scale - values as opposed to percentages (ex: dBm)

[sirjeannot]

Is your feature request related to a problem? Please describe.
Would it be possible to have scale defined as values rather than percentage from 0 to 100%?
The plugin auto fills in with the "rest" of the scale, and having negative values messes up the graphical representation of the scale

Describe the solution/feature you'd like
Have a drop down box with "values" rather than percentage.
Having the bandwidth to be an optional info on a link as it wouldn't be needed in this case.

Additional context
This comes in handy to graph levels in dBm, q factors, SNR, which are comparable for different links without a reference like total bandwidth.

thank you