If it was me........ I would mount it in front of the compass. And not spend the extra money on someone re-doing the helm. You may want a bigger boat, I did!
On my last boat I went with a two 7" screens. A little bigger boat, a Sig 290. But I get it have a bigger screen.
That sounds like an interesting, simple approach, but I'll need to get some measurements to see how it might fit; I'm inclined to think it might be too tall. The unit comes with a mount that is flat on the bottom, which would rest upon the slight curvature of the shelf where the compass sits. Some sort of shims would be needed. I should be able to access this area from the bulkhead inside the head, just forward of the helm.
I'm thinking that for now, during the boating season, I would look for a way to attach the unit's bracket to a rectangular piece of thick PVC or acrylic, attached to PVC cylinders that are inserted/fastened into the cup holders. All cabling could be routed through one of those cylinders to the NMEA2000 backbone below and in the bulkhead. Therefore, minimal alterations for now.
BTW, multiple screens sound nice! Simrad also has an ultra-wide unit that looks awesome.