I'm none too sure. Technically anytime you let the ties harden the bot's a multibot. I think we need some sort of firmer rule distinguishing a bot using ties in some manner to feed and a bot that delibratly ties to family inorder to form a shape or perform some action(50% sharing, cost reduction, etc.). I think the MB league already has some rules about what constitutes a MB.
Just checked, it says the bot is not allowed to feed while in SB form. Now it's anyone's guess on wether or not that includes a bot using unhardened/hardened ties to feed, but not tied to another family member, is a MB or not. :(
By all rights every strictly share feeder/TF(and SF when tied) would have to be included as a MB.
Endy B)