I have a Ventana El Gordo that I really like, currently set in a single speed belt drive configuration. What annoys me a bit is that the chainstays can be run as short as 438mm, but because Gates recommends reserving at least 10mm for tensioning the belt, I currently have them extended to 450mm.

Recently I came across this build from English Cycles where apparently the bike was designed with chainstays properly sized for the belt length, with little room for adjustments:
Superlight Alfine | English Cycles

My guess is that the belt was stretched or "tensioned" by hand. The obvious drawback is that, should I need to replace a tube in the rear wheel, it would be a PITA. Then again, it seems like the only way to keep both a belt drive and short chainstays. Or I could use an eccentric bb and no longer use my Next sl cranks (30mm spindle), but that would also suck as that is the lightest available and I like it lightweight

Or maybe use a configuration that is a compromise, where I leave only 6 or 7mm for tensioning the belt, getting me at ~444mm chainstay length?

Sorry for the longish post, what do guys think, other than just use a chain?