And will always break down somewhere.

But in this case I think that that code sample is clearer when written as:
\nif (keystroke < 10)\n    do_something_trivial(keystroke);\nelse\n    do_something else(keystroke);\n

Conversely if your list was a list of, say, random item IDs that got special treatment, then that case statement, written that way, would indeed be a complex thing. I'd strongly prefer to have you give me some context about what the commonality between the items is. If need be by hiding the list in a function with a descriptive name like gets_ira_tax_break_1234(item).

Cheers,
Ben