Well, tbh, I haven't put it on yet. However, I got two other samples either side (commonly in the uk they're "light tint" and "dark tint"). I can't remember the light indexes on these, but dark lets less light through than the 36% and was TOO dark. The light was too light (and let more light through than the 36%). So I'm pretty confident the 36% will be fine.
I think I just made that WAAY more complicated than it needed to be.
Greta value too - came well packaged + plexi in good nick. Can't remember how much the bezel plexi was, but wasn't much. Maybe ask them for samples?
Also - don't forget to get your marquee plexi whilst you're at it.
I went for 5mm on my bezel plexi. Also get some Vuplex and a good microfibre - polishes the plexi quick and effectively.
Great to have another Uk builder!