Urban PiAware tracking planes ~35miles out, ~40k high. Any better?

Okay, after re-reading Do I Need A Filter? and seeing the pictures above, it seems I need a filter to improve my range. However, I thought I read from many people (not necessarily on this board) that the pro stick plus with an external filter doesn’t have much of a change.

What’s the recommended course of action to proceed with at this point?
a) External filter
b) Some kind of isolation for better reception?
c) gain adjustments? where, how?
d) something else?

I understand it’s best to have the filter connected as close to the antenna as possible, but I don’t know if I want to have the filter outside in the extreme weather we have in Nevada. Is this a legitimate concern or is the filter weatherproof?