I went back and searched TLowe's split port post; Tom fabricated siamese port splitters much along the lines that I was considering after rejecting the notion of splitting the port only up the head bolt boss.
Version 2.0... I'm now thinking of removing the head bolt boss as is done for the lump port. The vertical port splitter can be formed around a new head bolt boss tube which is inserted in the opening where the original boss was located. When the splitter is properly located in the port, the head bolt hole and the splitter can be overbored and a steel sleeve pressed in to secure all parts. I'm sure that an appropriate epoxy would be needed to seal the waterjacket.
Like Tom's splitters, I don't think that an airtight division between the halves of the ports is critical; just trying to get the bulk of the airflow and the injected fuel into the correct opening.
The big advantage that I can envision for this approach is that curved horizontal blades could attached to the convenient splitter to serve as turning vanes. Very often in both aerospace and in powerplant airflow applications, turning vanes can make a short radius turn act equivalently to a much longer radius turn. Could this provide the benefit of a lump port without reducing the port runner volume as much?
Welded-in turning vanes would also seem to provide increased resistance to vibration/metal fatigue of the splitter tongue.
