We used to offer exactly what you're talking about. The old N3S model used a BG Neo3 PDRW with a deep back cup along with a pair of M130 woofers (not sure about an X variant)


Danny and I worked on designing a custom waveguide for the GR Neo3 last month which will work well with a back-cup and we've got a design we're really happy with. So we're excited to get the samples back and possibly reviving the old N-series that will sit between the X and NX kits in terms of performance.
Here's one of the final prototypes:

We sent the samples of the waveguides off too the manufacturer a couple weeks ago.

We currently expect the GR Neo 3s back in stock by early April.
The waveguides and deep cups may take a little longer however.
Good news is that the cabinet plans won't need to change from their original designs.
We are also working on a smaller center channel that uses the T26 and M130 drivers, but with the delays in getting them, made that's still on hold unfortunately, until we have it them back in stock so we wont need to go back and change the crossover due to differences between the new and older T26 units.