Check this out, if you haven't already:
John Sayers' Recording Studio Design Forum • View forum - Speaking of Speakers
Half of the threads are about soffit mounting, but there is a lot of good info.
Sayer's site is fantastic.
I am absorbing (ha) information from there, here and Studio Tips.
All three seem to generally focus on different areas.
This may be Forum Profiling, but I go to Sayers for construction and tuned trap info.
I am here for porous absorber info.
I go to Studio Tips for straight up theory and math.
On all three sites, there are great, generous people with amazing knowledge.
All three seem to love superchunks.
I find that interesting, so I'm going to build them.
I keep peeling away layers of the acoustic onion.
Everything might not be immediately applicable to my current building, but I won't be there forever.
That's a great way to think about your dining room.
It seems that it would add a quality of life aspect to your home when you are actually living in it, as opposed to working in it.
Thanks,
Seamus