Really fun challenge! I first tackled the challenge the simpler way using just three dice, but then I ended up creating an app that allows a user to enter the number of dice and number of sides per dice to dynamically find the most common score(s).
Some of my colleagues and I get together every other week to work on a Weekly Challenge (previously in a room together, but over videoconference for now!) This was the selected challenge this week, and since I had already done it (here), I went with a macro this time.
We decided to have the option of completing the challenge as given, or building a macro that would allow the user to enter the number of dice and number of sides on each die. We calculated the score = [highest side] * [2nd highest side] + [sum of remaining sides]