[Bedwyr]

That looks like some GoG Galaxy regression and the best thing to do is to contact their support for help.

AEL is a multiplatform launcher which means it does not have Windows-specific code to control window behavior. There are utilities (Google a bit) you can use to control windows and processes from the command line. With such utilities, you can create a CMD of BAT file. In this thread there is information about such utilities. Use google with the parameter site:forum.kodi.tv to restrict the search to the forum only.   

Understood. I'll keep up with GoG development. Their new Galaxy client is actually really good (it'll ingest a bunch of game services cleanly; very clever acquisition of user data) compared to the old one. And this does look to be a feature they had but haven't implemented in the new client.

In the interim I've discovered Playnite. To other people trying to do what I'm doing--get UWP programs into a gamepad controllable launcher--this github open source software does a very good job of a fullscreen interface: playnite.link . One can just create an AEL launcher for that or, if they're ambitious, edit the Steam launcher add-on to accommodate Playnite (or GoG or whichever game aggregator is one's preference). I already use Steam and Launchbox. This may be my go-to for all other services including Epic and the XBox Game Pass. 

If you use Launchbox as a frontend I'm very interested in your feedback in order to improve AEL. For example, things in Launchbox you love which are not in AEL, etc. 

That's kind of tough for me to answer because I use it as my sole retro gaming interface. AEL I just use for the arbitrary exe launchers rather than aggregating games. I can give some guesses at what I like about it at least, maybe that will be helpful.

- The experience of a retro console interface is primarily about the bling for me. What I like about Launchbox is that the default interface collects the kind of artwork that replicates what I remember about owning these games: the cartridge, the tuckbox and its art (I use 3D boxart collections for this), the logo on the selection wheel, and especially the autoplaying movie snaps.
- It just works with most any controller.
- Viewing options are very very granular. I can enable or disable most any visual feature such as movies playing as the background, not having a background, etc.
- The search heuristic is very good and I get very good access to correct problems in each entry (this is something I feel is a Kodi weakness; especially when I'm battling finding the exact title of a given movie or series. Kodi's philosophy seems to be either it's automated or it doesn't work. This perception might be out of date or wrong, but it's my impression).
- Loading and exit screens with excellent timing as the emulator takes its time to load into memory.
- Very robust emulator and platform handling systems, especially for Retroarch (correct command-line configurations, etc).

Much of the visual feel gets at the arcade nature of Hyperspin, but in a much cleaner, easier to manage interface. Hyperspin was like a front-end for XML data entry. It was arcane and frequently difficult to manage with different backend components. And the visual experience is probably 7/10 of the whole thing. I want it to be pleasant, seamless, and gives me as much of a feel of popping a cartridge into my SNES or N64 as possible.

All this is without a lot of in-depth knowledge of how AEL handles it's emulator functionality. I do hope the impressions help.