Looking good.
I think you want to know that electron is officially supported in this theme :
https://github.com/DTEAM-1/cygnus-blue-flames
We are working on it here :
https://retropie.org.uk/forum/topic/29961/request-for-artists-working-on-themes-needs-for-lr-mess-mame-additions
If you want to, then you can join in.
It basically work to support our project with a supported theme for the special systems :
https://retropie.org.uk/forum/topic/29682/development-of-module-script-generator-for-lr-mess-and-mame-standalone