I worked with GNU Radio quite a bit at one point a decade+ ago, even writing a custom C++ block, but I almost exclusively used it via Python rather than the GUI toolkit. I found it much quicker to mess around with flow graphs in code than their various UI frameworks, spawning windows as needed when plotting waveforms / spectra etc. The GUI as you said was too cumbersome.

I understand that they were trying to make a pretty complicated topic more approachable, but I always felt the push to GUI was misguided. Maybe they would have had more luck embracing the “S” in “SDR” and making programming languages the primary development paradigm.