creating an account in those other chains with my same STEEM user

Yes, at the moment, as written above, the recommendation to create an account everywhere seems to me the only option. But that's terrible! Which "normal", interested in blogging person registers under these conditions anywhere at all?

If only the content is copied, I suppose the same plagiarism rules would apply.

Even for "plagiarism" we use no clear measures here. The whales keep out of flagging, then nothing comes for a long time and small users are ineffective. The attempt to establish a large delegation account flagging from the community has already failed twice. "Club votes" are more important....

abusers don't seem to waste any time looking for loopholes to exploit.

Hm, the world is bad...

Nevertheless, on the Day of Resurrection, Happy Easter to you and your family!