The FP in two cycle oils in more about shipping handling and storage hazards then it is performance. Once it's mixed into gasoline what do you think happens to the FP? Exposed to 1200f combustion temps AND mixed with gasoline, does a 10-20 deg difference make any difference.
The only real way to make the oil 'hang around longer' is either to run more of it in the ratio, or use oil that's blended with higher molecular weight stock, mineral vegetable or syn, doesn't matter. Usually marketed as race oil.