Your LT-40 weighs 9.5 lbs on floats? That's incredibly heavy - what are the floats made of?

The LT-40's big wing will be a problem in any crosswind situation, and you will have to be very careful turning across the wind. Holding up aileron on the upwind wing (i.e. as if banking into the wind) will help but when taxiing you don't have much airflow over the wing so the aileron authority will be limited. Ask me how I know ...

I have my LT on slightly oversized floats with fairly tall struts so that it stands quite high in the water. This avoids sucking water into the prop except in very rough windy conditions.