Here is another vote for Martelli. They do make a 60mm and it positions your hand and arm correctly when you cut. There is a learning curve, but well worth it. You can order direct from
https://shop.martellinotions.com/erg...y-cutters.html . They have big sales once or twice per year, but the regular price on their cutters is reasonable.
Second choice would be the Olfa ergonomic. If you use this one, place your index finger on the top where the grooved texture is. A lot of people don't do that and they don't get the full benefit of the ergonomics.