Basically you can use single poles with handle ties as long as there are no line to line loads on the MWBC.
edit to add: I know 240.15(B)(1) says with or without handle ties, but it doesn't make any sense because it also says except where limited by
210.4(B). So you can't have a MWBC with single poles without handle ties. BTW the "without handle ties" part has been removed from the 2011 NEC.
As you said, 2011 changes the language because it did not 'correlate' with 201.4 - looks like it was Bryan Holland who submitted the change.
10-29 Log #190 NEC-P10 Final Action: Accept in Principle
(240.15(B)(1))
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Submitter: Bryan P. Holland, City of North Port
Recommendation: Revise as follows:
(1) Multiwire Branch Circuit. Except where limited by 210.4(B) Individual
single-pole circuit breakers with or without handle ties with a means to
simultaneously disconnect all ungrounded conductors per 210.4(B), shall be
permitted as the protection for each...
Substantiation: Section 210.4(B) negates the proposed deleted text of this
proposal. This revision better correlates the two sections and helps to clarify
the intent of 240.15(B)(1).
Panel Meeting Action: Accept in Principle
Panel Statement: See panel action on Proposal 10-30 which meets the intent
of the submitter to provide correlation.
Number Eligible to Vote: 12
Ballot Results: Affirmative: 12
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