Is your department of motor vehicles not responsive? I was successful in getting vegetation removed at a problematic corner (also cleared more myself after they cut offending vine covered scrub trees). This was initiated after watching a neighbor run the sign and almost get rear ended by oncoming traffic. If you can make a strong case for safety, you may be successful.
I imagine the lot of us fanning the country and demanding safe intersections.
Before:
View attachment 834549
After, 100' visibility from sight of sign to parallel with sign:
View attachment 834550
Of course, though the sign is finally visualized by FSDb, it is ignored :-(