I’m currently using a Marbella KR6S. It’s a 2ch with small footprint. By comparison, even a Blackvue DR590 looks huge. The guts are in a separate unit that can be placed out of direct sun. But downloading recordings is a bit of a pain - must be done over internal wifi connection with an app. A 1 minute recording takes 1 minute to download.
I don know anything about the Street Guardian SG9663DR…also a 2ch small format cameras with separate guts (which includes a tft screen). Looks interesting.