I had 1 issue getting PreShow to work in Kodi 21 Omega.  It originally wanted InputStream Adaptive to play all the videos.  I turned that off and everything appeared to work as expected.  I'm going to looking further into this when I get time.

Please post your experiences with PreShow Kodi 21 Omega here.

Working for me. My primary sequence is:

Dim Hue Lights For Trivia > Trivia > Trailers Intro > Dim Hue Lights For Trailers > 4x Trailers (in local folder) > Feature Presentation Intro > Hue Lights Off > Movie

My Shield just updated my Kodi. I was able to install PSE, but right now I am having problems with my skin. I used arctic zephyr reloaded, but the mod is not working with the new version... which skins do you use with kodi 21?

This won't fix your problem, but as a recommendation to people that may see this, please turn off app auto updates on the shield.  I am still mad about it modifying my system after I had it dialed in and not being able to quickly get it working perfectly again.