Catalyst Audio have a couple of tube based modules: VCO, Noise Source, Mixer, Filter and VCA. The VCO and noise source actually use tubes to create the sound rather than "warm them up".
The VCO has a pair of tubes, one for each side of the wave which gives some interesting configurations of waveforms, with wave folding and PWM, plus a feedback path that adds some unique resonant shapes.
The noise source has a number of noise sources, with the option to tune the noise to sound a little like a filterbank (to my ears).
The Mixer uses a tube to add drive at the output stage. They are aiming to be ready to ship by Jan/Feb 2023 - prices tbc.
Gets an update
It truly is a bass synthesizer
plus viewer questions
Engine enhancements, MS-20 filter and more