CFI is not required (by the FAA, company requirements might) At my company, if you never held any CFI then you had to do an extra day of ground training covering the fundamentals of instructing. If you ever held a CFI then that was covered in the FOI test for the CFI. Also as an LCA, if you've kept your CFI current, it allows you to renew the CFI based on being a current LCA (at least at the FSDO near me) so no sitting in front of a computer for 2 days or instructing and signing off students on the side.