Another question. How do you suggest implementing forms2.js? In the header on every page? In the footer on every page? Using GTM?
The forms2.min.js library should only be loaded separately from the <form> element if you have a range of different forms that can be used on the page (in different parts of the DOM).
In that case, you do only want to load the library once to eliminate extra network requests. (Note the library determines that it's already been loaded, so there's no functional risk to loading it more than once, only a bandwidth impact. But bandwidth is important, esp. on mobile.)
If you want to load it once, by all means put it in the <head>.
I wouldn't advise putting it in a tag manager unless you're very careful with load order. Lotsa pages out there trying to use MktoForms2 before it exists.
Otherwise, keep it with the <form> element followed by the <script> with loadForm() (i.e. the default embed code setup).
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