Incase it's a return ticket, wouldn't the TSA need a name match between the boarding pass and the passport, on the return leg? (Likewise for some other airports). That might make initializing a problem.

I'd book online with a truncated first name and surname (it's not going to print on the bp beyond the first few characters in any case - my full name is FFFFFFF MMMMM SSSSS, and the bp usually prints SSSSS/FFFFFFFMMMM, missing the last character of the middle name), or, call CX reservations to book.