I agree ... this could easily be done with a few creative engineers and architects in the room, haha. Consider that the current Horseshoe has a capacity of 9,800 right now. The temporary bleachers in the image below had 2,200 additional seats, and they obviously fit in the space between the stadium and Kirby. So, 12,000 seats (very poorly spaced out, but that is another conversation) fit easily.
Additionally, looking at this photo, there look to be FOURTEEN "missing" rows at the front of the Horseshoe ... if those temp bleachers (which don't even span the whole width of the Horseshoe) added 2,200 more seats, filling in the front area would allow at least that many, IMO.
So you easily have 5,000+ in capacity to work with within the existing space. That is not to say we need 5,000 additional seats right now, it is more just to illustrate that we have a lot of room right now that is not being utilized well. The end goal to the Horseshoe should be to build the tallest, largest structure possible with the most modest capacity, IMO ... right now we are doing the opposite - as many seats as possible packed into a small, unimpressive structure that is too far from the field and at too gradual of a slope.
EDIT: There are also a lot of cool architectural and spatial things we could do with having the stands extend back into the air OVER Kirby and adding a skywalk to the SFC parking lot ... I believe we once floated that idea as a sort of grand plan.