My preliminary wish list

It would be useful to be able to configure the markers with exact position (sample) and exact frequency via a dialog box.

Dynamic rulers
SL has the potential to be able to compensate for pitch variations of the recording (old tapes) or singers.
For this it would be nice to see a pitch deviation curve over the whole time domain.
One would have to determine the deviation of the momentary tuning to a value, which corresponds exactly to the momentary target tone.
The frequency sensitivity would have to be adjustable. Then you could see if there are pitch variations over the range of music. . I am thinking here of a capella choirs and wind orchestras. Furthermore, SL would also be suitable for other measurements, such as synchronization fluctuations and the like. In addition, it would of course be useful
if one could compensate these fluctuations by means of SL in the recording.
However, it is possible that this feature could be contrary to Steinberg’s sales philosophy, as VariAudio in Cubase provides similar functionality. However, VariAudio is not able to continuously change frequency corrections over a larger time range. For example, with a drawable, graphical curve in SL, it would be possible to achieve a pitch change over an entire piece of music. This could lead, for example, not only to compensation of changing intonations, but also to very interesting psychological effects.

Additional unmixable instruments:
Guitars, Flutes.

Note names and cents

Speed optimizations:
My processors are only running at 20% capacity.
My RAM (64GB) only to 25%.
GPU hardly visible utilization
Nevertheless, the program jerks.

Markers: you can do this in Project > Markers and Regions… and Project > Spectral Markers and Regions… Although you can edit using sample unit. This could be improved in the next version.

Dynamic Rulers: Good idea.

Additional unmixable instruments: Not answering specifically here, but more unmixing (generally speaking) is planned in the future.

Statistics: Can you detail a bit more ?

Speed optimizations: Do you experience slow spectrogram refresh while moving/zooming ? If so, what’s your CPU and your GPU ? Do you experience it even with one layer and default settings (FFT Size 3072, FFT Resolution x2) ?

Markers: Thanks, I found the settings.
But it would be good to be able to access
these settings via the context menu when clicking on a region.

Sorry, I meant sample, not statistics.
With sample, you can read the frequency.
There the output of the note name would also be interesting.

It is sometimes a bit difficult for me to find the correct
English menu items even in the help, since I usually
speak German.

With the default setting it is of course much better,
I was just surprised that the CPU is hardly used
and yet the performance drops so much. I will be more
careful in the future not to go too high with the
FFT resolution.

Intel(R) Core™ i7-5820 CPU @ 3.3GHz
NVIDIA GeForce GTX 1070
on a 4K Monitor