Also, changing the app itself is an option. The $LARGE_CORPORATION infrastructure works for other apps, if it doesn't work for the acquired app, it's not a give

Also, changing the app itself is an option. The $LARGE_CORPORATION infrastructure works for other apps, if it doesn't work for the acquired app, it's not a given that the infra must add features but perhaps rather the app should be restructured according to $LARGE_CORPORATION habits. Sure, it will take work, but if according to OP the alternative is to wait a full quarter, then changing the app might be possible in that time.