Actually the top ridge-line that I drew here dips down a little (4in), similar to a Nemo Meta 2P but not nearly as drastically (close to 8in i think)
The concept, is to take a single walled tent like the Meta 2P (just keep referring to that but SMD Haven or Lunar Duo as well as a handful of others are very similar) and shrink it down as much as possible without sacrificing sleeping area. That meant rotating the people 45 degrees and offsetting them slightly but it appears to work.
There's not a whole lot of head room but the sides are pulled out by the 2nd pair of trekking poles so it should help out to make the 36in height feel roomier. This could easily be made larger (42-48in tall) without adding a lot more weight but it just depends on what you want out of it.
For reference, here's the thread I have going on a MYOG 2 person tent:
I was trying to estimate weights on the one I'm making, which will be quite big for 2 people, and came up with 35oz for a single-walled or 40oz for double walled (detachable, netting/floor) as I haven't quite settled on which I want yet...I'm just working on the fly for now and will figure out the base when I get to it. This is including zippers and but not stakes/poles, thread, or seams and seam sealing...so add another 2-4oz to that and it should be pretty close.