Well we can put that one to bed then!
Hard to say, as a view from an Austrian like me.
He seems to be happy, when he gets called into the Austrian squad. Maybe I am wrong, but it seems that this is his major priority. He does not seem to be missed at RB, when he is not constantly playing and something tells me, his fine with that. But let us see, how the tide is turning, when Rangnick is not happy anymore, when it comes to less playtime in his RB club.
Baumgartner is a very good MF within the Austrian team. Never want to miss him. But without practice?
In my opinion, OG could evoke the best out of him. Which would make his starting spot in the ÖFB safe.
My assessment would be: if there is any chance to get Baumgartner, do it. OG knows his "buddies". And Baumgartner is a beast, when released. Pressing, overview, technique, speed (in the MF, not near the box). He could be a risk. But better a risk with qualities than noone.
Just my 2 cents.