Who makes the best turntable belt?

I’m in need of a custom turntable belt made to the length I specify. This is because I changed the motor on my Vpi Classic 4 to the new SOTA motor which has a different pulley so the optimal length was not known. I have an Origin Live belt which is pretty good but it has a small amount of width variation. I’m not sure if that is a factor in the measurements I’m seeing. Complicating matters is that I specified too long a belt so I cut it down and spliced it several times with super glue until it stopped slipping on the pulley and gave good measurements. But through this experimentation I’ve determined a length which is yielding 45.00 rpm, +- .01%, .1% w/f, as measured by Platter Speed, which is slightly better than what I could get with a VPI round belt. So now that I know the exact length I need, I’m wondering if I can do any better. A Basis site I was reading was describing how they have achieved an ultra precision ground flat belt and how it makes a big difference, but that’s for their own tables. I will be speaking with Origin Live next week. Maybe all I need to do is re-order their belt since I now know what length I need.