Might as well use what you bought. It's a light boat and it's level now. Not sure about the smaller trailers, but the larger ones have some built in camber and toe in. Having it level will get you longer tire life. And just in case you go over a dip in the road, your less likely to drag your skeg.
I do think you should have searched a little more for a drop ball mount that would have fit you receiver.
Here's one on amazon. Curt MFG. Class 1 1 1/4" Ball Mount Hitch
https://www.amazon.com/Curt-MFG-Class-Mount-Hitch/dp/B0052KB4KI