Upload & Sell: Off
I'm in Canada dude, it's like -10 outside, and the sun ain't that strong
Dude yourself. I'm in the Canadian Maritimes too. Maybe you assume you will only point your lens at the sun when it isn't strong, but I don't. Further, even in the dead of winter, the sun can be plenty strong enough. People have started fires from lenses made from ice on cold days. Maybe you will point the lens at the sun from inside your house; perhaps you even heat your house above -10 outside temperatures. I'm not assuming either way, just cautioning. If you are so smart, you bought the lens?
Sun may kill the growing fungus, but not spores that may be hidden in the recesses of the lens away from light. Further, you still have to disassemble the lens to clean the fungus off the lens after it is dead or has stopped growing and hope that it hasn't etched the glass.
However, I have my doubts about sun killing fungus, since it is the UV-C rays that are the killing rays and they are blocked by glass. (Glass is more transmissible to longer wavelength UV; hence UV filters for film.)
Probably most times people think sun has killed fungus is that they put it in the sun for a while and then change the storage conditions to dry storage which is what stops the fungal growth.
I'm sorry you think I'm joking and perhaps I'm wasting my time writing for you but there are others who read here and may take caution. Do what you want.