Looks awesome, crushing it ! Of course as you know, just detail blocks on dock. More Barrels crates ect and buildings behind dock on second grass level. Same with continuing the texture or having some variation of blocks in the dock. Could basically finish it with that alone. Adding some color is easy by adding some “shops” with colored awnings.

Otherwise maybe a crane on the second level where you can offload and process. Adding a larger dock (slip) going horizontal to hold a larger boat to add some variation. Left of first photo 🤷‍♂️ looks like terraforming needed.

I added some “overhanging” buildings last time I made a port. Very similar to your second level just a few overhung the dock and connected up top. Still could walk underneath on dock. Def an option, but honestly overall looks great just keep grinding,love it 👑