I haven't used it, but couldn't you use the mobile version of the useragent string?
Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/W.X.Y.Z Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)
A bit of excessive, I know, but I would love a 6.35mm jack, too.