Rick makes some very good points.
The primary reason for the short length of the Hane is not to minimize weight – the difference between 2.7 and 3.0 oz is just about meaningless, after all – but we've been finding that the longer rods are indeed tougher to use on small streams. While they extend reach, that extra 2 feet is a lot of reach and it makes it tough to fish in tight quarters.
The 7:3 was chosen so that the short length of the Hane could still power out the standard foot line, with plenty of tippet, if you did need a longer reach. I've used the 10'6" line + 6 to 8 feet of tippet without reservation with the Hane, and that gives me the reach I need for the majority of situations I encounter, including alpine lake shorelines and the banks of bigger rivers.
Where the longer rod really benefits you is when you are fishing weighted nymphs below the surface and need to mend line, or when you are casting a ways out in complex currents and you need to mend. You gain a little range on the longer rods – but not as much as you think – it's not a 1:1 relationship because the rods and lines are not parallel to the water surface.
The real design feature we were shooting for with the Hane is its very short collapsed length, so it can be stowed inside or on the side of a small pack without sticking out, and its reinforced outer tube so the case can be discarded. The little bit of added durability is nice because I also use it as a rear pole for my flat tarp (I find myself using trekking poles a bit less these days, and often carry only one, if any), and I rig it as a pole extender so I can use my (one) trekking pole with a pyramid tarp, with a simple round lashing using P-cord or similar along the grip.
It also stows completely inside a packraft paddle shaft :)
Having said all this, I still plan to keep my long (13') Tenkara rod for bigger water in the off season when I'm mostly nymphing and streamer twitching.