See a example of the plugin working here:
The Pro version of this plugin will allow your forms to submit as much as 5MB of data. That’s over 1,000 times more data than the free version. This is because the Pro version uses Session Storage. This means you can have a ton of fields and steps more than the free version. (File uploads are still only supported on the last step.) Session Storage has been available in all major browsers since about 2010.
Please make sure you try out the Free version of the plugin first and see if that works for you. If you try submitting your form and you are not receiving all the information in the email or you just don’t want to risk losing data when the submission gets too large, you can upgrade by clicking the button below. The Pro version is exactly like the free version except that you can use it on large forms with unlimited steps.
Currently the Pro version REQUIRES the WordPress REST API and Contact Form 7 AJAX submission to be enabled. By default these settings are already enabled.
WHAT IS TRACKED?
Data is collected for every site (or sub-site in multisite installations) the admin opts in for or that has an active license key. Most data-points are collected on a weekly cycle, and only if there are changes. Some events like license activation/deactivation and plugin activation/uninstall are collected immediately.