jm ÜØË,æ\ëâƱ_joÌ`0P!¹5;ä{ê&§LSounds right. Still, say BU chooses ABC, and a BU miner adds a transaction that ABC clients reject? I now believe such a setting would lead to 3 blockchains.
https://whatsonchain.com/tx/3d9395fbca6286aa923c7495a51a9d1b64f4f6a332190639ab3bcf6e22662529