The marker list is great to have, i use it all the time, very often with up to 15 markers.
Although sometimes it’s kind of hard to read when you for example print it out on paper (for which you have choosen light colour scheme for the white background)
Would it be possible to use the free space to the right of the Phase/Delay/Gain rows?
In that case any peaks in the spectrum would not obstruct the text.
Or maybe just black text in the top left corner, just above the “Atten: xx dB”.