I tried using the importer in the teleporter to upload a blacklist of websites.
I put 2.6 million websites into this format:
[{"id":2101255,"type":1,"domain":"website1.com","enabled":1,"date_added":1592921510,"date_modified":1592921510,"comment":""},
{"id":2101256,"type":1,"domain":"website2.com","enabled":1,"date_added":1592921510,"date_modified":1592921510,"comment":""},
{"id":2101257,"type":1,"domain":"website3.com","enabled":1,"date_added":1592921510,"date_modified":1592921510,"comment":""},
{"id":2101258,"type":1,"domain":"website4.com","enabled":1,"date_added":1592921510,"date_modified":1592921510,"comment":""}]
I incremented the IDs from 5 all the way up to 2 million and gave them all the same value for date added and date modified. I called the file blacklist.exact.json and turned it into a tar ball with this code tar -cvzf backup.tar.gz blacklist.exact.json.
Unfortunately, the teleporter didn't work for me. I went to teleporter import and then deselected every option except for blacklist (exact) and deselected clear existing data and found the tarball.
I got back two options, depending on the size:
Empty token! Check if cookies are enabled on your system. pi hole
The file you are trying to upload is not a .tar.gz file (filename: backup.tar.gz, type: ). Please try again.
I cleared my cookies and tried with multiple browsers. I tried with progressively smaller files and went all the way down to 50,000 and it still did not work.