If a trustee determines that an allocation between principal and income required by ORS 129.355, 129.360, 129.365, 129.370 or 129.385 is insubstantial, the trustee may allocate the entire amount to principal unless one of the circumstances described in ORS 129.215(3) applies to the allocation. This power may be exercised by a cotrustee in the circumstances described in ORS 129.215(4) and may be released for the reasons and in the manner described in ORS 129.215(5). An allocation is presumed to be insubstantial if:
ORS 129.350