Good luck with that, it's your choice.
You may be right, you may not. Truth is none of us will ever know. However, what i will say is that last time the tyre form got really bad (around 3-4 years ago i think) Schumacher did do something about it and they spent a fair bit of cash over hauling the mould, and initially they were very very good. There was a small decline after maybe 2 years, then there was last year when i totally agree they weren't really good enough.
Will GRP produce the same vollume of tyres and build completely new moulds every 2-3 years?? who knows, I certainly don't and it's not fair to speculate. Let's hope they do! then maybe they will never have any quality issues in any tyre that they sell.
It's a fact of life that moulds wear - just have a look at any of the components for an Associated B4. When i built my origional kit, the bits just fell together. I haven't built a recent kit, but from what i understand the dremel/file/sand paper needs to be kept to hand to make the bits fit. It's a fact of life unfortunately.