Hey @quadlifepro, when you say lightest ripper possible I immediately think of the ultralight whoop. But that's 6mm motors and I hear you talking about 8.5's. I must say I prefer the ultralight whoop over 8.5mm, even for outside. It has better performance (TWR) and has zero damage on crashes. I have only broken ONE ultralight whoop frame ever!
With 8,5 I used to break frames all the time. I used to fly 8,5 for the performance but after the ultralight whoop, there is not much reason to fly 8,5 except a little bit more wind resistance and a slightly longer flight time. But for a backyard ripper I'd still stay ultralight whoop, unless you have a huge backyard but in that case I'd go micro brushless.
Regarding the Micro85, it's a nice simple frame but it had less thrust compared to what I was used to. Probably due to the props being closer together. It did fly OK so it might be an option if you insist on 8,5mm.