turns out obs is pretty powerful.
Other than bespoke synth:
using flatpak obs-studio and waveform plugin.
GIMP 3.0 using built in render animation and effects such as lava.
Scene comp:
3 waveforms.
2 gifs with color correction filter.
1 png with color correction filter and scroll effect.
and screen capture layer of course... with color correction filter.
The color correction filter allows you to change a layers opacity aka make it transparent.
changing the blend mode settings around for each layer resulted in this.
auto-generated closed captions where not intentional interesting none the less.