Absolutely get the Class 1 now, make sure there isn’t anything underlying that would stop you getting a Class 1 at a later date. Then let the Class 1 lapse and fly on Class 2 privileges (which the Class 1 gives you) and then just make sure you book the Class 1 renewal before the 5 year mark.
It might cost you the price of a renewal more than not getting it but you don’t want to invest time and money if the Class 1 threw up something unusual.
That would be my advice.