Most people agree that the best thing for coral growth is hitting natural seawater levels for almost all nutrients, with a few targeting a bit higher for mag and calcium. As far as trace elements, there's no evidence that an abundance is helpful in any way, and likely is more harmful than anything if your tank isn't already deficient. If you're looking for more growth in your coral, you're much better off testing your alkalinity, calcium, and magnesium and dosing those accordingly based off of your test results. Those are the elements that are readily depleted by coral growing their skeletons and can be measured.
In your case, I still wouldn't dose any trace elements. With you're water change schedule, you're likely very close to natural levels for trace elements, and adding even a partial dose carries the risk of building up those elements in your tank which can be harmful.
If you're still not convinced, maybe try thinking of it as a daily vitamin. If you're already getting as many vitamins as you need through a healthy diet (water changes) than taking a multi vitamin supplement (trace elements) will only serve to overdose you on them. Will this hurt you right away? probably not, will it help? Probably not. Long term, who knows.