Battlegrounds - DR minions duplicating on full board

Quick question - when I have a death rattle minion that pops with multiples - if there is no room on the board - they only populate one new minion. I’ve noticed a few times that some players manage to make them populate back to back (meaning if there is no room, the first one attacks and dies then another pops attacks and dies, then another one pops attacks and dies) - I just played with someone who had 2 golden Dread Admiral Eliza’s and a golden “death rattle duplicates twice” minions and 2 golden Scallywags (how they got all those goldens for the perfect setup is suspicious as well… but not my question) - I lost from the time the first scallywag attacked because she just kept duplicating even though there was only room for one. and each time she duplicated the increase stats from Dread Admiral Eliza was already included on popped minion.
I’d noticed this before on a smaller scale and tried to play the scallywag in the same way (without all the goldens, but again…how?) but she would only pop once for me even with the duplicate deathrattle minion in play.
So now the question - how do you make the deathrattle minions keep duplicating when there is actually no room on the board for more than one?