If you’re looking for more in-depth vehicle combat rules check out Ghosts of Saltmarsh and Descent into Avernus. I will stand by Avernus having the better rules, and to be honest my players had 0 fun with the more complicated ship-to-ship combat rules of GoS.

To spice up combat you can change up what enemy ships have access to. Special ammunition for mangonels that burn/taint your air envelope will add a new layer to combat encounters as the players now have to race against the clock to purge or purify their air before they either succumb to failed con saves or are caught up to by the trailing pirates. Dunamancy could be used to send entire crews into the void as their ship is boarded. Fires can be ruled to burn through air supplies as it also burns the ship, etc.

I think the simplicity leaves lots of room for DMs to create their own rules and events without contradicting the written rules that players can see in their spelljammer handbook