I have done it. Wouldn't go longer than 40" on the older style 1" boom riggers. Newer style 1 1/4" could handle around 50" booms. Scotty uses a telescopic boom to add strength when extending all the way. (over lap of 1" and 1 1/4" boom even when extended to 60")
Note, the longer the boom, the more stress to the mount area. Make sure it is a solid mount.
Not sure if you have a metal supermarkets on the mainland, but I was able to get 1" for $5 a foot.
Both styles are replaceable.