Basically that is what is called "world hopping" and people do it not only to bypass the ore portal thing but also to not advance one world with bosses or just use the extra one to collect other resources etc.. People even did that a lot in having a solo world and playing with others in multiplayer.

Personally I have done it a couple of times and it always felt like cheating to me. Just my personal opinion. I have made worlds just for building and when friends shut down servers or rolled over to a new world we would split stuff up to take... but I only need one world packed like that and haven't bothered since.