I've done the same type shooting over the years, with good success
rate.

I think 1 oz. is minimum, 1.5 oz. is better. I favor 30 lb.
line........and I only use monofilament. Mono is "slicker" and will
slide over branches better than other types line.

As you found, patience helps......give the wt. plenty of slack line,
and leave it hang. It'll usually gradually drop lower and lower.

Also.....winter is better time to do this, when most trees have lost
most of their foliage, especially in the North.

Lee Carkenord KA0FPJ