It’s unlikely that this is an issue, in general CMS work in a way that doesn’t require outside scripts to be loaded by the template, they are normally loaded from local storage. In most cases loading outside resources is considered bad practice and if its absolutely required you can load an outside script without defining its protocol:
[CODE]://some.cdn.com/script.js[/CODE]
Realistically even if there were some tweaks required it may add 5-10 minutes to the migration but honestly the improvement of having SSL enabled is more important than the slight time cost of resolving any issues that may arrise.
The signup and signin pages also use the same template so enabling SSL on those pages wouldn’t change the fact that in the unlikely event of incompatabilities it would be an issue either way.
