Thanks for the info. The laws of science be a harsh mistress...we'll see if it becomes usable enough with the R710 (I mostly want to be able to do FaceTime/Google Duo calls with my kids to my parents from the backyard as they play this summer...). If not, I think I will see if I can find a cheap enough Rx10 unit (I gather those are the ones that are not yet EOL and still getting Unleashed firmware updates?) and mount it under the eaves.The external modules are similarly numbered but are prefixed by a T, not R. They are significantly more expensive though so sit down before hitting ebay up! At the price the R models are available Id be inclined to mount one in a sheltered location and see how it goes. Putting one in some kind of plastic external box probably wouldn't affect range and may help with rain protection etc.
I subjectively guesstimate an increase in range of about 10-15% moving to Ruckus from Unifi. They can't defy the laws of physics so tin foiled insulation will still be an issue, but there is likely to be a slight uplift which may just push it into the range of useable.