Thanks galfert, I'm a bit shy and some people on some forums (not you, not here) tend to get upset when noobs don't follow the netiquette in place, and that netiquette isn't always obvious to newcomers.
So, here's the back of my house where an Ecowitt HP2551 all-in-one will soon be installed (waiting for Father's Day deals which Ecowitt confirmed to me were coming).
I've got 3 options for on-house installations, by order of personal preference (i.e. where I feel the most comfortable climbing to):
1. On the lower end of the rafter, which is about 12' high. I'd use a ~40 inch J-Mount to raise the station above that part of the roof. That section of roof (covering the patio) is made some sort of thin white semi-transparent plastic.
2. On the chimney, which isn't being used at all. The top of the chimney is a bit higher than the apex of the roof. I'd also probably use a J-Mount, raising the station above the chimney. The roof is covered with red-orange shingles (I think made of fiberglass).
3. On the gable, which is about 17' high. I'd probably use a gable mount there.
What I like about #1 is that I can easily access that height with my ladder, and would also be able to access the station ~40 inches above for cleaning and battery replacement. What I am unsure about it is that south-east winds would be blocked by the entire roof (that corner of the house is pointing north-west).
#2 would probably be easy enough to access, but I am uncomfortable having an ungrounded metal pole pointing up above my house, and I am not DIY enough to install grounding myself and don't want to pay someone to do it.
#3 scares me. I'd be at the max reach of my ladder to install the mount on the gable, and would be unable to reach the top of the pole from my ladder. I'd have to access the station (installation, cleaning) while standing on the apex of my roof, very close to the edge.
So bottom line is: my mind is pretty set on #1, but if that location is really bad for wind readings then I'm willing to consider other options. To be clear: I'm not looking for perfect readings from all sensors, I am very much aware that an all-in-one is all about compromises. As far as wind is concerned, I really don't mind having data that reflect the micro-climate of my backyard/house surroundings, but I still want those wind readings to be representative and useful.
Thank you all in advance for your feedback!