I'm not sure if you have already tried Formulaire or not? I can give you access to the demo forum if you wish to see how some features work before purchasing, or you may subscribe to the extension for 1 month or year on Extiverse and I can refund if it doesn't fit your needs.
DCar with respect to downloading of the user submissions, would this download include all the data the user entered on their profile?
Using the "export" feature that's part of Formulaire, you get the data of all the custom fields, as well as a few attributes that are native to Flarum, like email and username. If you created multiple profile forms to create multiple tabs in the user profile, each of those forms has to be exported separately. But you should be able to merge the data together with external software based on the user ID or email if necessary.
The extension does not offer migration from FoF Masquerade at this time, but it's something I can add if there's demand.
DCar ensuring consistency in 'topic title'?
Unfortunately not, Formulaire only validates the custom fields. The original title and body are still there and left for Flarum or other extensions to customize. I could add an option to completely remove the title and/or body if those don't make sense when used together with custom fields.
I hope that answers your questions! Feel free to reach out via email if you would like access to the demo or want some additional screenshots.
