I usually go with 10x, which is the fastest I can get with the tools I use without going through twice.
Sometimes I'll speed up less-interesting segments even more (100x).
Then on a few videos I've had to speed it up more like 20x-30x to keep it from being nearly 20 minutes long.
I'll also...
You'll want some idea of what power level will achieve your speed goals. You can be pessimistic and overbuild power-wise, but then costs go up. Off the top of my head I'm thinking 120hp (90kW).
On weight, you can try to determine how much weight you'll lose by removing the existing engine...
Thanks Hillhater. I have a J1772 inlet I can use at some point. Initial version is using the Smart Plug 30-amp inlet:
https://smartplug.com/product/smartplug-inlet/
We have J1772 connectors around here too, just not on the water's edge yet.