In a rare moment of 9-5 nonbillable geology work I submit:
The four observations you list (added below in italics) as some of the differences between the Owyhee and GC intra-canyon lava dams are some of the exact same ones I note in the manuscript that is collecting dust on my desk at home.
1. Volume of lava vs. volume of water
2. Mode of entry: canyon rim cascade vs. tributary valley route
3. Severity of topography (vertical and lateral trajectory of lava incursion)
4. Proximity of volcanic vent to the canyon; abundance of pyroclastic material.
This is fabulous! I look forward to hearing more about these items and your other GC observations.