I think the way you’re doing it (an if statement with a condition using the $?VAR syntax, which evaluates to 1 if the variable is set, and 0 otherwise) is probably the most idiomatic csh construct that does what you want.
I think the way you’re doing it (an if statement with a condition using the $?VAR syntax, which evaluates to 1 if the variable is set, and 0 otherwise) is probably the most idiomatic csh construct that does what you want.