I had a recent issue similar to yours. I have a change node with 76 rules and by the time I got to 40 rules, it was becoming very tedious to do all that scrolling.
Plus, I discovered that my rule sequence was important because when a rule is satisfied, the node continues scanning the rest of the rules. (I thought the node would exit when a rule is satisfied). For example, I am entering the node with a (string)number and when found, change msg.payload to an information string to be displayed in a Text node on the dashboard. I originally sorted the rules from shortest to longest. I.E. 123 would come before 12345. The node changed 123 to the text string, but it continued scanning the node rules and changed the 123 in 12345 as well. I fixed this by putting the longest rules first.
But with 50+ nodes to move about, this became tedious quite quickly.
My solution, and a workaround for your issue was to export the change node to a text file, then run the JSON data through JSON Formatter tool to make it human readable. I then edited my rules in the text editor. When done, I imported the node back into Node Red.
Hope this helps.