You bring up a good point and that is definitely a concern. Only counter argument I have is that RCV doesn't make things worse.

In NYC, they let you rank 5 candidates. In Alaska, they have a primary that is essentially plurality and top 3 go into general where RCV determines the winner (it was 2 Republicans and 1 Democrat in the last election).

There are definitely ways to solve this that can be done on computerized ballots and on paper ballots. We can print a 20x20 grid of bubbles, I am sure. Alternatively, use a computer to create the list that is then printed, scanned and counted (so you have a paper ballot that can be manually verified and an electronic count for a much quicker result).