The taxi will not have an issue going to Trellis, but as others have mentioned it is very walkable if you have rolling luggage. If the cooler doesn't have wheels they will need a taxi.

I was just at Scrub for a night and I think your idea of being on the dock with a drink is a great idea. You can enjoy your full day at Scrub with the pool, good food, good service, and your guests can arrive in a boat big enough to carry everything comfortably and enjoy their first night in a great location.

Lots of sailors on TTOL like to run around and pick people up in different places and cater to people. I don't have as much experience and that works for some people, but for me it's my vacation too. I'm not running a ferry service so if I want to spend a night or 2 on the dock for my convenience and the crew needs to take a ferry, it seems to work fine for everyone.

Personally, I'd stick with your Scrub plan.

Cheers,
Jason