Hey folks!
in addition to support for undo/redo (in NME and NGE), I added a new node to allow creation of loops: Introducing loop support for NME by deltakosh · Pull Request #15599 · BabylonJS/Babylon.js (github.com)
Documentation PR: NME loop documentation by deltakosh · Pull Request #1197 · BabylonJS/Documentation (github.com)
I also added a new button on the frame to switch them into a focus mode so you can see only the content of that frame 
Enjoy!