Nah cant get that silicone out of the mold. Need other silicone. But cant find ones over 300 deg…
I have some of that stuff in my collection of useful items. It’s going to be challenging to remove air bubbles from the mold (but does that matter?) and it’s a relatively strong adhesive. It’s not particularly runny or fluid either. If the mold can break apart at the edges and you can get the insert out, it should do the trick, at a bit lower cost than the true molding products.