Thanks for the update, and improved structural engineering, on the landing gear.
It may account for some of the increased weight in the R90 vs other 50cc sized planes. I think most of us would trade a few ounces for a more robust LG structure.
We ended up doing it anyway with the R70!
With your empiric data on performance, I think I will equip mine with a DLE55. It is always an option to swap out the engine for something larger later on.
A question on servo sizing; i don't dispute your experience with ~100 oz-in servos, but readily available calculators for required servo force seem to indicate that a larger servo could be required, especially on the rudder:
For example, to deflect the rudder 38 degrees at 55mph (which one might do in a knife edge) would require 75 in-oz of torque; it would be easy to require more torque (in excess of 100 in-oz) with a bit more rudder deflection, or a few more mph. Also, I like to size my servos so that they never see more than about 50% of their max load as a safety factor - but that is just me.
Do your calculations on servo size include a safety factor? What do your calculated loads, particularly on the rudder and elevators look like?