Looks like they are starting to appear on Amazon!
https://www.amazon.co.uk/Clode-Released-Replacement-Milanese-Stainless/dp/B071YC2W5T/ref=pd_sbs_200_1?_encoding=UTF8&refRID=VQNRZC5SV43R2DEHMXY5&th=1
Does a leather 3rd party strap exist at the moment?
I haven't been able to find it anywhere.
Just got a steel blue 3rd party strap from ebay, although there is very little cosmetic difference with the strap, I did notice that the quick release clasp that holds the strap to the pin is much shorter then the official strap. Which makes me wonder how the strap with hold the watch in place when doing energetic actively.
Leather bands are starting to appear it seems.
https://www.aliexpress.com/item/Carprie-New-Luxury-Leather-Strap-Replacement-Watch-Band-With-Tools-For-Garmin-Fenix-5-GPS-Dropshipping/32820059864.html
Look seems ok, but leather quality could be a problem, I got one for Fenix 3 and although was usable, the leather was too stiff. So if anyone gets one please report here what is your conclusion. Thanks