My advice is to listen to your gut and do the psych ed testing (assuming that paying for the testing doesn't result in financial hardship).
Being "average" in math is fine for kids that are "average" or "a bit above average" in other things. I don't mean that in a tiger -mom kind of way but in a searching for clues kind of way if that makes any sense. We all aren't perfectly even in our abilities but having a large ability spread could be a sign of an LD which if that is the case I'd want to know about sooner than later. Many gifted kids can have undiagnosed LDs because they are able to fit into the "average" category despite the LD. It can be years before it becomes too much for their gifted side to compensate for.
My DS7 is 2e and getting tested was the BEST thing we could have done for him. His grades in school were average but that didn't fit with the extremely smart kid we saw at home. It was early on and we weren't really stressed but when his behaviour at school started to be an issue we tested. One of the biggest pluses from the testing is that DS now knows that certain things are hard for him but it isn't because he is "stupid" (as a 6 year old that was his only assumption). He was extremely frustrated by his challenges and having an explanation greatly increased his confidence, happiness and helped him deal with his frustrations in a more constructive manner.
Of course YMMV but I have no regrets. Having more info has helped us (and the school) help him in so many ways.
