Hi Peter,
Yes, the firmware is 100% micropython now, with heavy use of the @asm decorator

.
With this device I wanted to show that
micropython firmware is a reliable alternative for C firmware in terms of production systems running useful, mission critical applications., as an inspiration and encouragement to other fellow micropythonistas,
Micropython on a scientific instrument offers the advantage of math, filtering and processing operations embedded on the device. A nice example is "the real-life colorpicker" calculating the R G B values out of reflected spectra (not as easy as it seems), or Normalized Difference Vegetation Index, which is interesting for plant growth and climate change researchers.
Time and the advent of 5$ MPUs have shown, that any advanced math or obscure data filtering of raw values should be done on the user side, because every user has different needs and ideas of how the raw data should be processed.
That is why we tried to reduce the functionality of the device to the bare minimum: a sensor should measure and send data over the USB cable.
I would be grateful if anyone could comment on
"which groups of professionals care if a scientific device runs micropython, linux or a proprietary firmware + software?"
Fifty years of scientific instrumentation made the market appear to not care at all about customizable firmware.
Universities and industry cares more about solutions to their specific problems and customer support for getting to the target quickly...
They accept the world of nice, filtered and smoothed-out sensor data, even if it's a lie.
Any thougths?