2 things .... Park it on Centre stand But Also Tell him NOT To keep topping up the oil level!!!
I used to have this problem on my 1200 the solution was a moment of clarity When a BikerMate told me how his R100GS paralever burned a lot of oil if he topped it up and It stopped when he let it get down to about a third from the low to the top mark, at this stage It near enough stopped burning oil !!!
As I said to him, "That would be to do with two 1/2 litre paint cans slapping up and down the bores and smashing the schite out of the oil!"
Basically Once its down to "It's own level" it stops pulverising the schite out of the oil and getting sucked through the induction and burning off
So with my 1200 after a good run out I leave it on the sidestand for 5 or 10 mins to allow the oil cooler to drain down (thermostatic valve) while I get my gear off and then I go out and parked it in the garage on it's centre stand Check it then or before riding off
I check in the sightglass and as long as it is 1/3rd full I am content
It used to use a litre plus between services as I nanny'd the fucker topping it up to full
Once I realised what a twat I was and stopped topping it all the way to full! It basically nearly stopped burning off oil completely