In the case of a taxpayer other than a corporation, the amount allowed as a deduction under this chapter for investment interest  for any taxable year shall not exceed the net investment income  of the taxpayer for the taxable year.

The amount not allowed as a deduction for any taxable year by reason of paragraph (1) shall be treated as investment interest  paid or accrued by the taxpayer in the succeeding taxable year.

There is no mention of a carryover allowed "by reason of" failure to elect to itemize under IRC 63(e).  I think that the carryover would be properly reduced by net investment income, even in a year where the taxpayer takes the standard deduction.  That said, I've not had to take a position on a tax return regarding this and I haven't looked at Regs or case law, just the IRC.

Rick