Regardless...
You can add the AP certificates to your MDX at any time (meaning next month, next week, today... this morning, if you are so inclined.) You add them by inputting their numbers.
Once they are in your MDX, you don't have to worry about accidentally destroying (or losing) the original certificates at home.
They cannot be accidentally activated. They can "just sit" in your MDX ready for activation at least until the end of the year 2030.
If you really want to "make sure," just add a "fake name" to your MDX account and transfer the new AP certificates to THAT name.
Also, if they are sitting under your real names, you can book advance FPs with those certificates in the MDX.
When you are finally ready, you can activate the certificates to "live APs" at any time while you are at WDW. The activated APs will not start counting down until you actually enter a park gate using them for the first time.