Kodi Add-on/library question

I came across an amazing add-on and am just trying to do a little integration with what I’m running presently. At the request of the add-on creator, no accolades will be given and I only wish I could share it with you. THAT being said, if you search long and hard as I did, you will find it. My question for you folks is this: I have a library of movies and tv shows. All of mine are in .mp4 and .mkv format. This person has them available through their add-on but as strm files. I haven’t yet found a working converter. Can anyone speak to whether or not it is possible to merge a local library with one offered in a repository? TIA!