It’s an ancient lost beta, that is somewhat reserved for “official extension from the game developers”, so the linked extension doesn’t fit into this category.
Not to my knowledge no
And as you are not the developer of the extension, just a moderator for a channel, you can’t apply for it as it’s not your extension, nor is there a process for it, and additionally the extension isn’t an official extension from the developers of the game.
As per your linked github issue, POE’s extension is by GGG whom made POE. So it’s an official extension created for the game by the game dev. (ignoring conflicts from two installed extensions for the same game theres other issues with autoenablment but I digress)
You can use the API instead and do it yourself
Couple this with eventsub channel update and you can do it automatically when you receive a game change signal
No need for the extension to have access to this undocumented/lost beta, when you can do it yourself from a channel level instead
There are also other issues around this regardless of using the undocumented feature or the API to switch
The streamer could just leave the extension on the whole stream unless they need to switch to another game matched extension.
And if left on the extension ought to switch to a sleep mode as the selected/target game isn’t active on the channel. But might just switch to a info/non real time state mode. shrug
