Currently the plugin will delete all the info from all the fields if you submit and it finds an error. In the UX world, this is considered undiluted evil. Why is the plugin punishing me?

Furthermore, the UX writing is profoundly unclear. The field marked "application folder" is actually for the MYSQL database name. Who would ever figure that out?

If you really want to make it good, don't force the user to enter any of this stuff. Just make an "export settings for the migration plugin" button. It can create a key code that includes all the settings. Copy, paste into the single field in the plugin, click.

Other plugins have this functionality, so you probably won't have to reinvent any wheels.