@franzli, I can look into it - give me some time, should be able to get back to you in the evening (in 6 hours or so), the only thing I've noticed so far, that background apps are getting killed, on the launch of a new app in the launcher interface (at exactly that time) - because I can exit Google play music (back to home screen), and reenter it via the dropdown notification - while it remains playing (it doesnt even have to be on the "allowed in the background list" to be able to do that), but as soon as you launch another app, it gets killed.
My apps for changing the screen orientation, as well as the TTS apps survive the launch of another app though (with them being on the whitelist) - so perhaps...
On the other hand if alt tabing is opening them in a "freshly launched state"... Seems like their hook to change that behavior is pretty deep in android at that point.