I’m wondering what benefits can be achieved if I use my metal fence as an antenna for UHF/VHF reception. Is it advantageous to use the 6-foot high fence vs. a normal "rubber ducky."
You won't find it effective at those frequencies. The higher the frequency, the shorter the antenna. That fence, depending upon its length, may make a killer shortwave receiving antenna
Check out this link Antenna Calculator
key in a frequency you want to find an antenna length for, and you'll see what I mean. For example, 488mHz only requires 11.5" of antenna for a half-wave.
an old trick (don't know is it worked) was to use a fence as a great ground for c.b. radio
with a chrome fender you would park into the fence and done!
some say it worked but i never tried it