When in a Java Realm and you are looking at a wall or floor of maps on item frames it grinds the entirety of the server to a halt for all participants. This is consistent. If the area with said maps is not rendered when the realm is first loaded there will be no noticeable effect, however, if you access these chunks tremendous lag ensues and then when you walk out of range of them there will be persistent periodic lag spikes that are brief but intense. This continues indefinitely after the chunks with the maps have been loaded but the chunks are no longer loaded no matter where you are in the world until the server is reset with no players.

I understand this was said to be fixed in 1.16.0 in patches MCPE-41584  and MCPE-59791 respectively but I have clear evidence this is not the case and is debilitating to the performance of the game.