Thanks.I think most people would suggest directly overhead or just in front of the main listening position overhead (even if mounted high on the side walls instead of the ceiling) would probably be the best location for only having 2 overheads as that puts sounds in a place nowhere near the 5.1 locations (i.e. more noticeable). However, two front heights are certainly better than none and if you ever expand to 4 overheads, you can leave them where they are and just add the rear speakers. Most AVRs will tell you where to connect it for only 2 overheads.
I currently don't even have speakers for that use, and the only plausible placement currently is front heights near ceiling. I can do rear heights but then I have to deal with more long cables etc, which I rather not do for now. Atmos is fairly redundant for what I watch, so I like to try it but I'll barely use it.
Ah, so the AVR will suggest how to assign them when it runs it's pre-calibration test. Looking at the back it has Heights 1 and Heights 2, and not specified terminals like I thought. I guess I can play with the assignments after and see what's sounds best to me. The manual has lots of options on how to assign them. When I'll get some speakers, I try to figure out which ones are what you called "directly overhead or just in front of the main listening position overhead"