If it’s a dink, you could remove it without unlacing the wheel.
The wheelbuilder would have straightened it out if he though it wouldn’t compromise the strength of the rim to do so.
But he also would have told you to bin the rim and built a new one in for you if he thought it was a problem that would affect tyre seating etc.
So just ride it and trust his judgement.
As a professional wheelbuilder with over 10 yrs professional experience and some high profile customers, it looks to me like he knows his stuff and as you’re on 1st name terms, he wouldn’t want to let you down.
Having said that, there are no guarantees with any damaged products, and you’re just making a judgement call based on experience.
So if it doesn’t work, he’s just tried to save you some cash based on an assessment he’s made on the condition of the rim.
A Flow rim is stronger, and if you want to get a Hoop, I’d take it to Matt to get it trued to his standard as he sounds like a good wrenchman.