Change large amount of objects to be configurable via a setting in minetest.conf (max_objects_per_block).

minetest.conf.example

@@ -274,6 +274,8 @@
 # Length of year in days for seasons change. With default time_speed 365 days = 5 real days for year. 30 days = 10 real hours
 #year_days = 30
 #server_unload_unused_data_timeout = 29
+# Maximum number of statically stored objects in a block
+#max_objects_per_block = 49
 # Interval of saving important changes in the world
 #server_map_save_interval = 5.3
 # To reduce lag, block transfers are slowed down when a player is building something.