oseymour
Euphyllia Addict
IMO/IME
99.9% of the time this rehoming/upgrade never happens. You would be better off respecting the requirements of these creatures and buying fish that are appropriately sized for your system. But as said before, no one can stop you.
Where did you get that 99.9% number from? Are you pulling it out of a hat? I've re-homed a number of fish in the last 4 years. I either take it back to my LFS or find another reefer to sell/trade. In NYC there is no shortage of other reefers to do this with.
I've done it, have friends that do it, have people in local clubs and local events that I attend do it. I'm not saying everyone does but it happens more than you think.
Periodically browse the fish for sale forum in ManhattanReefs and you'll see the number of people looking for homes for new fish because they got too big.