Firstly, this isn't from the same developer. The plugin posted here is from wp-staging.com. I am aware the developer you mentioned has also a staging solution, but it't not the same one as posted here.Hi, do you (by pure coincidence) have their new Database Merging plugin https://wpvivid.com/db-merging ? If it so would you be so king to share...
Secondly, you should create a new request thread in the appropriate section for your request, this way we can keep things clean and don't confuse other members.