FYI - it takes a few reads to understand what you are doing.
This time I failed. I really dont know what EXACTLY it is you are saying or want.
Did you use my print trick to see what actially IS in 'FontcardTemplate' POST? Because if optn25 is empty, I THINK thats what you are saying, then you need to see what is getting padssed. Because the array command looks fine.

Confusing code, because if your select is on the same page, of COURSE it wont work, because nothing has been posted yet. The array stuff needs to be on the page that gets submitted to.

You have to remember, with PHP, stuff gets loaded in order. It is only with JS that you can go backwards.