Don’t see anything wrong with the request per se…
For example, this
…as an optional, additional view inside SL main display here
I’ve no relevant technical knowledge here… I’d guess, since we currently see the ‘upper’ waveform window and main spectral display area are tied to show the same (coloured) data according to the layers selected, it may be a tricky deal to allow unlinking these two, such that a new ‘Rainbow view’ be displayed there (waveform only) as an option.
The Spectral view/display would of course remain unaffected.