As to the question of what two IP people would look like testing each other, I think that Chinese wrestling and boxing would be closer to what it would look like. Eventually, one operating system would be left running. In terms of Aikido waza, I think that it would be like when kata evolves into movements done during kumite. My experience is that it typically ends up looking very different than how a cooperative waza practice looks. I do not necessarily look at this as a bad thing, just something that is likely to occur. I also think that it is important to be able to learn to use the internal form contained in the external form of waza, without being constrained by the external form.
Most people in the world have never seen anyone with descent internal strength who can fight in an MMA style or modern weapons in a manner that actually demonstrates unusual approaches and skills in that area that are recognizable as different on feel and approach. The vast majority of what is out there is simple push hands or external fighting. Maybe in time that will change and there will be some interesting observation offered.