What about "Nomacorc"?
Ok, I did some more searching and found this pdf file/website: https://corksupply.com/assets/Uploads/Nomacorc-SelectGreen-sellsheet-EN-US-Mid.pdf
This article shows that Nomacorc produces three synthetic corks: "Select Green 500" rated for 8 years, "Select Green 300" rated for 10 years, and "Select Green 100" rated for 15 years.
I bottled all of 2018 with Normacorcs and I think I have them figured out. By the way-not 1 leaker in 300+ bottles. I used a mix of Select green 300 and 500.
Select 900 are their cheapest and likely shortest lived corc. But it's the one they designate for hand corkers. These are still available on Amazon, but I'm not sure they are currently made. They may be, I just don't know. I did use 1 bag of 30 of these and they seem good.
Almost all their other corks are "Green" (As in carbon neutral, they are not green in color). THey are a plant based (sugar cane) polyethylene.
Classic Green is a 5 year cork-entry level normal cork. This would likely be sufficient for home winemakers.
Select Green 500 is an 8 year cork
Select Green 300 is a 10 year cork
Select Green 100 is a 15 year cork
Reserva is a 25+ year cork.
Then in each of the cork types there are 2 or 3 different lengths. 37, 44 and 47mm
Honestly, I think they are great. My Italian corker had no problems with the Select Green corks. No creasing, no leaks nothing at all.
Supposedly they control O2 ingress and publish the rates on their website. And the closure age rating, does corelate to O2 permeability. I think the sweet spot for home winemakers is probably the Select Green 300s. You can buy bags of 1000 on Amazon for about $250. The shelf life seems pretty infinite.