good luck with the test, I forgot to get my test for plastic melting done
No worries! This kind of trial and error thing takes way too much time.
In the end I hope these will be suitable for use but I don't know if they will be. The real question will be is if they can be a replacement for broken plugs. So the structure has to be at least equally strong as the plastic plugs. I haven't had any breaks but I have been careful with them in my tests. And I have noted scoring from pliers. But even if it turns out to be a waste at least we will know.
Btw the new mold solution I got is 1,000 times better. Sculpey brand mold maker is ok for half molds but it is not durable. I do not recommend it. New mold maker is castin' craft easy mold brand. Costs like $20 but soooo much better.