There’s a few mentioned in the aftermarket thread, Hermès is the most oem option you’ll get, The only thing that annoys me about third party bands are the lugs, which is why i gave away my nomad strap to dad ( he doesnt use it either) The leather quality on that is lovely for the price,, but the connector was loose and too bulky looking, ugh
Absolutely love Clockwork Synergy bands. Connectors fit great and the leather is super nice and high quality. I own a bunch of their bands for other regular watches too. There are also many Etsy sellers that make high quality stuff, but the connectors may be hit or miss.