I noticed I could not just copy over my favorite rms files like forest nothing, bamboo prison, fn 7x7, forest prison. While they would load, they would fail to spawn either the town center, or the villagers, but only for some players, like 2 out of 8 players would spawn with no TC sometimes. In most cases increasing max_distance_to_players from 0 to 4, or from 5 to 10 would fix this. This is likely due to trees being in the way, which was not an issue in HD as the trees could be in the town center (the part of the TC that units can walk under) Now the scripts are strict and do not allow this so instead do not spawn the TC
To get the game to spawn the correct number of villagers (i.e. 6 for chinese, 4 for mayas), do not set number_of_objects for create_object VILLAGER. I had to remove that line from several maps I ported.
Here are the maps I fixed a while back, I added " DE" for ‘Definitive Edition’ to the end of the file names so as not to collide with unfixed maps that people published.