Another alternative would be to use one of the attraction wheelchairs to go on the accessible boat.
They store several wheelchairs at the Handicapped boarding area for people who may have an
ECV or rollator, but may not be able to walk on.
one little story about the difficulty of getting up from low seats ....
A number of years ago, I was at Epcot with my daughter, who uses a wheelchair. We met up with Disboard member Cheshire Figment for the afternoon and went on several rides. He has since died, but was a large msn with bad knees.
I chose Figment (naturally, one of his favorites). That was no problem with getting in and off - I sat in the back of the wheelchair accessible ride car with my daughter and he sat in the front.
Then we rode the Mexico ride, which I thought would not be an issue since the wheelchair boat is very similar to Small World. He walked down the ramp to get in and had a little difficulty sitting down on the relatively low seat. When it was time to get up, he had a great deal of trouble getting up. I won’t go into detail, but that experience is why I say using the ramp to walk down may not be that much help.