I know OP already said they did not want another account, but in case anyone else looks at this thread later, my husband and I were just at MCO in April and saw banners for visitor toll passes.
https://visitortollpass.com/
This was quick and easy to setup; we did it on our phones while waiting for our luggage to come around and then stopped at the kiosk on the way out to the rental carts to pick up the placard. You put in your license plate # when you have it, then you can just drive through the tolls normally. We kept the placard the whole time, and used it for our second rental car when we got off the ship, then dropped it in the drop slot when we flew home. Easy peasy. The only gotcha was remembering to turn OFF the rental car license plate when you return the car. My husband forgot to and we got one charge for whomever had the car next. Even with that it was much cheaper than paying the rental car fee for them to pay our tolls.