Would there be a downside to that
Yes. Trying to make them permanent would make it difficult to address repairs when parts fail. If you’re sailing at all then you will experience parts needing to be replaced. Mother Nature is not easy to tame.
Better in your situation might be to use an anti seize product and then proper torque when tightening the screws. You will see some corrosion over time because you have an aluminum mast and stainless screws. The anti seize helps to mitigate the corrosion on the screw threads.
If that is not enough for you, use a product like locktite on the threads. It comes in various strengths. Locktite 243 (blue) is medium and a general purpose product that can still let you remove the screws when needed.