NEC wet location.

[Rjryan]

You did not indicate what type of wall the panel is mounted on. If it were a concrete wall in direct contact with earth ( Definition Location, Wet NEC 2023 Handbook ) Then 404.4(A) Damp or Wet locations Surface-Mounted Switch or Circuit Breaker: “ A surfaced-mounted switch or circuit breaker shall be enclosed in a weatherproof enclosure or cabinet that complies with 312.2.” Because the advice you have been getting is correct there is no specific code references between the hot water tank other than panel clearances, which you have met. And no rules about slop sink other than panel clearances which you have met.

It should have read from the 2023 NEC In concrete slabs or masonry in direct contact with earth.
I apologize for not quoting the complete definition of the wet location ( had nothing to do with any explanation in the Handbook just listed my source ).