I think that is a very generous interpretation of, "if the taxpayer can establish by adequate records or other sufficient evidence that the amount allowed as a deduction for any period was less than the amount allowable, the amount taken into account for such period shall be the amount allowed."

My interpretation is not that depreciation is optional, as you seem to imply, but rather that if depreciation becomes not deductible - for example a home office deduction limited by business profits then you would not need to include it.