I understand the reasoning, especially if Cust thrives. But Schuster is a ball player first and foremost, and I dont mean of the Glenn Stewart/Jake Trbojevic type. From what I've seen he is much more skilful in that aspect of his game than those two players, though obviously they are much more effective close to the ruck. And Manly's side at present desperately needs a good ball player.
It would be a serious waste of his talent having him taking on the grunt work of the forwards, where defence requirements would sap his effectiveness, just as it is presently doing to DCE. If he was to be a forward, it would have to be lock and with a roving commission like Menzies, though I doubt he would have Menzies pace (Menzies I believe started off as a centre in his junior days).
Schuster reminds me of a combination of elements of Wally Lewis and Cliff Lyons, both players 5/8s though Wally also played lock. Not suggesting at this stage that he will reach those heights, only referring to the skill set I've seen so far. It was one of the reasons Schuster was moved from a forward role early on in his junior days and made 5/8 and captain of his side, and he then apparently became far more effective.