Multiple independent cursors
I believe that only 2 cursors are possible in DTT right now. For some analyses, it would be useful to have more, and also have them be independent for different traces (e.g. Trace 1 has cursors at 19.17 Hz, 21.86 Hz and Trace 2 has cursors at 26.4 Hz, 30.91 Hz for a total of 4 cursors). I wonder if it would be possible to implement something like matplotlib's vlines, but in addition to being vertical lines, also be able to read off the orthogonal coordinate. Not sure if there is some inherent limitation in root that makes this difficult to implement though, just putting down a thought here...