A little bit ambitious and overly-optimistic if you ask me.
Not that your sentiment for the wish is ill-intentioned or misguided; it's just that when you consider and look at the trajectory and progress of Graphisoft's development efforts on ArchiCAD for the last 4 versions and try to extrapolate, it just seems overwhelmingly unlikely that such a wish could be fulfilled.
Especially when you consider all the "progress" made in the most recent version in AC14.
That being said, it would be pretty sweet if the Section/Elevation Windows along with the Plan were able to have a somewhat simultaneous interactivity with the 3D windows. Much like Revit does it. But with Revit there's a price since that interactivity begins to noticeably slow down much faster and drag down performance, the bigger and more complex your model becomes compared to ArchiCAD's 3D window complex model handling.
There's another reason why I think this is highly unlikely; well 2 actually.
Firstly, when you mention that they've disabled hidden line view for OpenGL, I don't really think it's so much that GS has disabled it as much as it is that they simply can't do it, as a basic limitation of OpenGL rendering and implementation. The point being that OpenGL probably has a lot of limitations that would make it unsuitable for (if not outright incapable of) 2D Documentation, and Vector output. as you would have to do with Elevations and Sections.
Why else do you think that you can only do 3D documentation with the Internal Engine instead of with the vastly superior (quality-wise) OpenGL engine?
Secondly, 3D window model renderings (be it through OpenGL like in ArchiCAD or DirectX/Direct3D like in other software) is a direct function of one's GPU or graphics/video card and not their CPU. Your plans, sections, elevations, are all handled by your CPU, (which is why ArchiCAD saw so much performance improvement in those windows when it became multi-core capable in version 12). Graphics cards are specifically designed and built to handle that specific kind of workload, but not the kind of information and data that is handled by the CPU.
And I believe that in order to do what you are proposing or wishing for, Graphisoft would be forced to rely on the capabilities of GPU's and multiple GPU providers rather than being able to control the performance and quality on a more standardized and benchmarked platform like CPU's are.
This is despite the fact that GPUs these days are rather powerful (with even the possibility of multi-GPU PC's) and offer more in certain areas such as with Real-time renderers that are now becoming more and more fashionable and standardized.
It just seems like there would be a lot they would have to give up in terms of capabilities, versatility and performance to make Elevation/Section windows OpenGL (and consequently GPU-reliant) than GS are prepared to do, (or possibly capable of, at this point in time).
I know that Revit's capability of simultaneous interactivity in all windows (i.e. move one element in 3D and see it moving simultaneously in all windows, as opposed to waiting for regeneration and updates) is implemented through how their software is coded and their 3D display is Direct3D and not OpenGL, I believe.
So the implication for GS to achieve similar performance might have to be a complete re-write of ArchiCAD's source code and to overhaul their entire kernel - something, which, I believe it has become abundantly obvious in recent years, that they are either incapable of, or unwilling to do.
Sorry for going on too long and too much of the tech-talk, but I believe it ties into larger issues of ArchiCAD's overall development and roadplan for the future, especially as it relates to, or depends on Graphisoft's capabilities and decisions.
