Ok, so the modular swappable playfield design isn't a new idea. Pinball2000 did it 18yrs ago. As an RFM owner I have given this design a lot of thought. Would I be tempted to buy a Star Wars playfield for it? No, not even if it was a good game. For me its just too much hassle and risks damage to one or both playfields. The spare playfield would need to be stored in its box somewhere dry. How much smaller is that box compared to a tombstoned machine? Not much really. How much easier would it be to accidentally damage a populated playfield in a cardboard box than a playfield in a pinball machine cabinet? A lot.
The selling point of the design is supposedly so that Operators can upgrade to the latest money taking game at minimal cost. The problem being that now they have one and a half pinball machines but only one taking in money, the other taking up space somewhere. The half a machine will now lie forgotten about somewhere for the rest of time or be sold. But who do you sell it to? Its not like selling a whole machine, your potential market is now severely limited to other owners of that platform which means its a buyers market and you will be selling at a huge loss, if you can even find a buyer. Plus your brand new game internals are now having to go into an old cabinet which may have signs of wear and abuse from years onsite which may affect reliability, desirability and therefore revenue.
Looking at the Heighway design they've improved on the idea by allowing swappable cabinet artwork. But how much extra does it cost adding that complex double skinned cabinet slot to every machine made? The vast majority of which will never utilize the swap out design anyway. Future games are then limited in scope by the initial hardware choices e.g. RAM, CPU, GPU etc
There's probably points I've forgotten to add but that sums up my thoughts on it.