The change in the threshold for materiality, from $500,000 to $350,000, impacts the auditor's approach to assessing materiality for the financial statements. The options provided pertain to different aspects of the audit process:

A. Key items selected for testing of additions to property, plant, and equipment would be impacted, as a lower materiality level might mean that fewer items of property, plant, and equipment would need to be tested individually to meet the reduced materiality threshold.

B. Substantive analytical procedures for various administrative expenses items could also be affected, as the auditor might adjust the level of scrutiny applied to these items based on the revised materiality.

C. Testing of control procedures for the sales SCOT (Sales, Collections, and Other Revenues) would likely remain relevant, as sales processes and controls are critical to ensuring the integrity of revenue figures, regardless of the materiality level.

D. Identification of insignificant accounts would generally not be affected by a change in materiality, as the focus during an audit is typically on significant accounts and balances, and insignificant accounts would already fall below the level of concern for an audit.

Therefore, the answer that may NOT be directly relevant to the change in TE is D. Identification of insignificant account.