[Fig. 1] Opera has Custom site panels for Edge's applications. Only 5 entries, alas. They can be opened in left sidebar (LSB).
[Fig. 2] Add Apps icon to Edge's toolbar among other FCHD icons (Favorites, Collections, History, Downloads). Then make it open in the right sidebar (RSB), just like FCHD panels.
[Fig. 3] Augment list in Customize toolbar with Apps option.
[Fig. 4] Continued from Fig.2. Simulation of Apps Manager opened in its own panel, like FCHD panels.
[Fig. 5] Let enable Apps Manager to encapsulate all apps within its own panel. Here's simulation for bab.la app. "bab.la" is a real Edge's app. I resized it and set "On top" in a window of IceWM X Window System. You'll find my system in short reading signature at the bottom of this post.