The Page Forms extension includes a number of JavaScript libraries, and all of them are at least somewhat in need of upgrading. In some cases, the library being used is already defunct and needs to be replaced altogether.
The JS libraries used by Page Forms, and the version being used of each one, are:
- FancyBox - version being used is from 2010 (has been replaced by fancyBox3, which is apparently a separate library - http://fancyapps.com/fancybox/3/)
- Select2 - version being used is from 2012
- Dynatree - version used is from 2013 (has been replaced by Fancytree - http://wwwendt.de/tech/fancytree/demo/)
- RateYo! - version is from 2014
- jsGrid - version is from 2016
jsGrid is probably not worth upgrading at the moment, because it's still fairly recent, and Page Forms' version of it has some customizations. But the others should all get upgraded.
In MediaWiki 1.30, the version of jQuery bundled in with MediaWiki jumped from 1.11 to 3 - and when jQuery 3 is used, it leads to JS warnings for at least Dynatree and RateYo!, and possibly some of these other libraries. Additionally, there are probably useful features and bug fixes that have gone into these libraries in the intervening years.