Define the learning goal first
If you want feedback on one movement, a session with a repeatable wave may make comparisons easier. If you want to improve how you read a beach, an ocean lesson gives a different kind of practice. Discuss the goal with a coach rather than treating either setting as automatically superior.
Understand the limits of repetition
A consistent setup does not remove the need for judgement, fitness or control of your board. Ask how the venue manages queues, falls and the return route. Learn the briefing for that specific pool rather than importing habits from another place.
Allow for the full cost of the day
Compare transport, equipment, changing time, coaching and cancellation conditions alongside the session price. The most useful option may be the one you can repeat comfortably. A discounted headline price is less helpful if the session level or logistics do not suit you.
Transfer skills deliberately
After a pool session, discuss which changes you want to try with an instructor at the beach. After an ocean session, identify a movement that could benefit from focused repetition. Keep a short record so your next session follows a purpose rather than a venue trend.