It should be possible to use the Fills Out Form trigger (and filter) with all the web page constraint options (Is, Is not, Starts with, Not starts with, Contains, Not contains, Is any). Currently only “Is” and “Is Not” are available choices.
Given that it’s often recommended as a best practice to use global forms for campaigns, rather than local forms at a program level, the lack of this functionality limits the simplicity of using the “Fills Out Form” trigger as a means of updating progression stages. Usually I have program-local landing pages with global forms, and if I have multiple landing pages in a program, such as in a A/B test group, I have to explicitly reference each of them for my program-local triggers to work. This is a pain to do, and can easily be overlooked. However, if I could use web page constraint criteria like “starts with”, I could easily reference all current and future landing pages in my program.
Plus, apparently with the current structure, the “Web page is” constraint functionality is finicky (see related idea:
Please fix the "Webpage is" constraint on the Fills out Form trigger and filter). It just makes sense to have the flexibility of using all web page constraints in this trigger.