Pinion gearbox + Gates belt drive - what are my options for 36-hole rear hubs? I currently have a touring bike with 36 spokes front and back, in the front with a SON 28, in the back with a Shimano Deore XT hub. I plan to switch my frame and I'm currently considering switching to a Pinion P 1.18 or C 1.12 gearbox with a Gates Carbon belt drive.

I thus researched what my options are for Pinion-specific single speed rear hubs, and Pinion itself only offers 32-hole rims. Also, the DT 240 are also 32-hole only. It currently looks as if my only option is a Deore XT or DT 540 Tandem hub with spacer rings to keep the rear sprocket in place. I've also found BMX-specific hubs, but I'm unsure if they are suitable for my needs, as I'm unsure if they have a freewheel ratchet mechanism.

Although I might change rims (26" -> 28"), it would end up silly having 36 spokes in the front and 32 spokes in the back. Do you know of any other options than standard hub + spacers? I should mention that I'd like to keep my 36-hole SON 28 and also not lace without using all holes, mainly because Roger Musson advises against that.
Hope Pro 4 Trial/Singlespeed Hub is available in 36 hole configuration.

Here is a link to the product page:
https://www.hopetech.com/product/pro-4-trialssingle-speed-rear-hub/

You should be able to source them through your local bike dealer or via the internet. The are available for quick release and 12mm axles so you should be able to fit them to your new frame.