I tested the oven tangkring by making some buns and bread this evening. It was something of a foolish yet courageous thing to do that I used a new recipe, as I didn't know how it will turn out. But alhamdulillah, the buns and bread turned out soft and yummy, and thankfully, well-cooked inside.
N/B: One thing, don't ever use old cheddar cheese blocks for your toppings. They get dry, burnt, and don't melt properly.