Minor aside to that; the US army just awarded a contract to Cummins to complete development of their new 2 stroke opposed piston engines.

https://www.cummins.com/news/releases/2021/07/30/us-army-awa...

Cummins and Achates Power was supposed to have delivered two working prototype engines to the US Army's TARDEC to be installed into a Bradley for evaluations in 2019. I'm assuming that they testing went well enough to prove that the engines are viable enough for further development.

Uncertain if the technology will ever meander it's way to regular car market, but interesting to see ICE development continue on.