If a trustee determines that an allocation between principal and income required by sections 557A-409 through 557A-412 or section [ 557A-415 ] is insubstantial, the trustee may allocate the entire amount to principal if one of the circumstances described in section 557A-104(c) does not apply to such an allocation. This power may be exercised by a co-trustee in the circumstances described in section 557A-104(d), and it may be released for the reasons and in the manner described in section 557A-104(e). An allocation shall be presumed to be insubstantial if:
HRS § 557A-408