This thread is beginning to drift into a "how to do it right" and a "what's right" pissing session.
I would ask if the OP has yet tried to mount the tire and see what the actual fit up results in. Does the OP feel that they can't just toss this tube, for whatever reason. At some point the value of moving on outweighs the cost of question or concern. Where that point is for each of us will be different. (just as how we mount tubes is different
)
When our industry last tried non butyl tubes (about the early 1990s and poly urethane IIRC, my shop sold a few Panaracer versions briefly but we stopped after both poor sales and growing dislike of the after use stuff like "odd" patching methods). While we had little issues mounting them, we saw little benefits and greater cost besides the patching and needing to be far more specific in the sizing. Andy