I've never used one of these type "fences" but my take
has always been that a fence serves to purposes, equally
important. Keep dogs in, keep other dogs or animals out.
The dog not wearing a collar can walk right in any time.
Strays, bigger more aggressive or male getting to a female
all can have bad effects. If this has been considered already
sorry, I just glanced thru the posts.

PKnTX