All cartographers who can trade me a map that leads to large graveyards cause serious freezes. Cartographers who do not have this trade do not cause any issues, vanilla trades for woodland mansion maps and ocean maps work fine. I can't check if the graveyard map itself is working properly because freeze does not let the map to load.

Hey, thanks for the notice! This is caused by mojangs slow searching algorithms. Sometimes the large graveyard structure can be extremly rare (x-times the mansion). When a cartographer with the trade spawns the algo searches for the structure to provide the map trade and this can take a long time (if the structure is not near) and causes the game to freeze. But in most cases the freeze should stop after some time.... I can't do much about the search-algorithm but I will provide an option to disable the map-trade in the config file, so you can disable it, if it causes issues.

Fixed in version 1.1