You can take a cab to FW, but it can't drop you off anywhere near Hoop-De-Doo. You'd still need to take an internal bus to Pioneer Hall.
The boat from MK, on the other hand, will drop you right by Pioneer Hall.
You can do as you'd planned; take the boat to MK and then catch the FW boat. Or, you could take the monorail from GF to CR, and get a boat to FW from there.
I would take the boat. No matter what, you'll need some other form of transportation (in the case of taking a cab, then you'll have to get a bus or a boat, depending on where it dropped you off). You could have the cab drop you off at the WL as well, where you can get a bus or boat - but why not from the MK?
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