There's a long way to go as yet, we could be anywhere from promotion to being in a relegation battle possibly losing more assets in January window in either outcome too!
If we had a poor season, and he had a poor season... Well, i don't know where that leaves this deal, in tatters i imagine!! :-/
The one factor i didn't consider was that he wouldn't be playing as their main forward, i just presumed he would. Another (cheery) thought is that he could be injured for 6 months as an example, and what conclusions could be drawn then if he scores in the interim period!? So many directions this can go. Like you posted earlier will be nice to see him smiling and enjoying his footy again... Far as i'm concerned he's still one of us.
If we have a great season, gain promotion and he hits 15-20 goals over there and is vocal in wanting to play the prem again, i wonder if there's anything in the buying agreement that is only applicable if we're still championship at the end of the season?