I never ruled out him ever playing another position, though majority of the contract he likely is still just a DH if he doesn't have the longevity on the mound. He can probably play a corner OF spot or 1B like you said, but do we really want him playing a position in his mid-to-late 30s just to squeeze out some extra WAR out of him if any at all, when you risk the chance of injury? His value is tied with his bat. Would rather him stay healthy and put up 5-6 WAR seasons like he did in 2023.
In terms of context, if he makes a move to the OF or 1B, likely would happen at the half way point or latter part of the deal anyways. For example, he strictly is DHing in 2024. In 2025, he'll be able to pitch. He either A) stays healthy and pitches at an elite level like he has, or struggles to get through 15-20 starts and becomes fragile like an Erik Bedard or James Paxton on the mound. Or he C) pitches more like a No. 4 or 5 starter which is meh. If option A, the question is how long does that last in terms of health and pitching at an elite level into his mid-30s? If option B, likely Jays will experiment with him as a starter for a couple of years even in this situation, so he would strictly DH still. Both situations likely have him pitching into his mid-30s. If Option C, he still likely gets a couple of years in pitching as long as he's not Alex Manoah bad. So the chances of moving him off DH and the mound to transition into a full-time OF likely doesn't take place until he's 34-35 at the earliest. And at that point, maybe he's just a part-time OF who plays 70-80 games instead of 150.
Only way he transitions to an OF or 1B spot early is if he gives up pitching altogether after 2025, which lets hope not.