Why not take the 6AM Speedy's from VG to Trellis and then cab over and take the 7:30 Smiths?
We did this on our last trip and made our 2PM flight with time for breakfast in CA. So easy!
Unless something has changed??? But I am still seeing all those times listed.....
This is the best (and really only) option.
Arrange your taxi from Trellis to Road Town ahead of time would be my recommendation.
Here is a link to the website with updated BVI and BVI -> USVI Ferry Times
https://bestofbvi.com/bvi-ferry-schedules/