If you feel that you want to instruct and that you will enjoy it.
Do it.
It has its rewards, job satisfaction when you see one of your students take their first pax up.
And it has its down sides of being !!!!e pay and treated like dirt by some employers (not mine i might add)
I know of approximately 10 instructors who have gone airline or Biz Jets in the last 3 months so the job prospects should be getting better for next year.
It all depends on your money as usual. If you want to keep your IR and MCC money in the bank do the FIC course. But if you want to be available for airlines you will need to get them out the way.
It may be worth leaving the FIC until Jan Feb so you get it just in time for next years summer season.
MJ