realolman has a point. You really would have a parallel feed at any point of the circuit. AC current isn't really directional. We like to think of it as hot and return because that makes things simple but that's not really correct. It's not going to matter very much where they are tied together.
I'm really glad this subject got posted because I have never given it much thought before now ( stuff happens )...
ME too... :roll: (Even though I've read; had to read it several times)
No one had talked about the neutrals here, till now.
Only a few circuits are technically called out as required for a house, why not keep them totally isolated! ? (And not a Code requirement! - IE it's not stated to keep neutrals separated - BUT it sure will show up with AFCI's)
I've said before I don't a whole lot of residential, but have run MWBC's and have kept the neutral's separated. Like a 12/4 w/ ground or a 12/6. Now I know a 12/4 isn't required for the 2 circuit kitchen application. But if you really think about it makes a real strong case for it, for all the modern things going into these grand kitchens.
But I can only think that it might well matter to keep any circuit isolated in this case (the Kitchen). One certainly wouldn't want to hang off the neutral of a MWBC or even bring more together, outside the panels neutral bar.
I don't want to argue about a manufactured bundled MWBC being a circuit, that's a thread line for another day.