Im niot up to speed on your back story but cant help but wonder what you have an appt with an endo for?
What exactly is it you hope to accomplish?
99% of the endo's are at best going to throw you on synthetic thyroid hormones because thats what they know. This approach MAY help with hyper/hypo symptoms but it will NOT fix the underlying cause which means all the other symptoms due to the deficiencies you suffer will continue to plague you and get worse.
They are not going to recommend a supplement plan and most likely their advice will conflict with that of a supplemental approach.
Just ask for a full thyroid panel if you can get it, the numbers really dont mean much at this point because chances are they will be within range and your symptoms will be your real guide.
Where labs will help is 6 months, a year or even two down the road after you have been supplementing. They will give you a baseline to compare to to judge progress although I still personally feel there are of little value except perhaps peice of mind.