Poor quality valves Topic is solved

[BlackBart]

Don’t you think you could make a pattern and 3D print some in some sort of…….plastic..?

“You’ll be fine.”

[Sveedy]

Well after going down many rabbit holes, I have finally figured this all out. I think.
I was mistaken when I assumed that my valves were the stock ones. It turns out that they were replacements, not stock.
The stock ones are embossed with numbers and weigh apx 46g. The smooth ones like I have are the TRW's. They weigh apx 41g.
I am going to go back to the stock ones, and keep the TRW's on the shelf. They apparently are N/A right now.

Moral of the story - Don't use ( or let anyone else use ) aftermarket valve stem seals. I can't explain it, but I've now lived it.