Update... As mentioned, I have the Duo Omega G2. The midrange horn is up top with the bass cabinet and tweeter under that, all mounted to the frame.
I settled on removing the holding screws of the bass cabinet, letting it rest on the frame below, and sliding it back about 20 cm to time align the tweeter with the midrange horn voice coils (as far as I could tell). I put some temporary books under the back of the bass cabinet with the front of the bass cabinet resting on the rear frame support.
If you look at the side, the front bottom of the cabinet is about 1 inch in front of the inside vertical side support. I angled the cabinet back with removing a book from the rear of the cabinet. I can just see the top of the bass cabinet when in the sweet spot.
What did I hear? Much better continuity. More smoothness and a natural sound. Before, there was a little bite and hardness, which is now gone. Doing the above also betters the bass timing with the midrange horn. I likewise did not hear any problem with the tweeter diffracting off the midrange horn. In fact, from my listening position, I can see the whole tweeter with space between it and the midrange horn. This mod is also pleasing in appearance.
This is a very easy mod to do. Later, I will experiment with spiking the bass cabinet.