Imo , it is a mistake to refuse their "comps' when offered. They can use that against you, and it invites more ROV.
I assume the sales a RE agent gives are cherry-picked to hit a number and that most will be lousy, but once in a while, they provide a usable one. The point is that the appraiser accepting their offered sales is part of the expectation, so I accept them with a polite smile, then say, "I always do my own research; however, additional data is always welcome, thanks," and walk away to prevent further discussion. The same applies when a homeowner gives me sales in a refinance situation.
I do not argue with agents or owners or offer false hope that I am going to use their sales. When I was a newbie, I used to try to educate them about what sales were good and which ones were not - now I don't bother. Most agents present laughingly terrible sales, which can indicate why buyers overpay. Agents can provide useful market-area info or whether they have been inside a comp.
It is good practice to include a comment in every appraisal that "additional sales and listings were reviewed and considered." No need to specifically mention the agent's sales imo unless an appraiser feels a need for it.