That seems a bit of a cheat
It should not be necessary for users of UE4 to purchase another product in order to code a form with which to use it. This is not mentioned as a pre-requisite in the sales documentation for UE4.
I find it surprising that the documentation provided with UE4 is missing large chunks of information that should be there for people to be able to use it.
I have used Web Assist products since 2004, and only now am I finding this mean attitude appearing.
It goes "Buy this product - its does this and this and this" - but when you do, you find that the paperwork is so designed that you have not much chance of using it without buying additional items or €50 a time support.
Why was it not pointed out before purchase that you cannot design a form to use with it unless you bought a WA forms designer? It did say that the form designer would help, but did not say bluntly as it does in the post above "You must buy ...."