Not sure. Diesels are dirt cheap and they work often enough to be useful, especially if you have more than one
There was a well known "innovative" company (my shares in it were down 99% when I sold them
) which tried to take on this market and totally failed. They did develop some generator technology which can work at the high RPM that you get out of a turbine and are trying to sell that,
AFAIK.
I suspect the existing engines will see most of us out...
100kW in 20kg would, assuming a small package and even high efficiency (say 50%) mame an impressive space heater
You'd need quite some airflow to get rid of that 100kW loss when trying to make a 100kW real output.