it only applies to the mapblock
you can make a craft using 256 mcd entries
you can make a ufo using 256 mcd entries
you can make a bunch of mapblocks for one terrain using 256 mcd entries
so best case 768 mcd entries in one "real" map
the limit is the map file format (one byte to link mcd entries)
in the oxc code its read as int (at least 2147483648 entries)
with two bytes in a new mapfile format you coudllink 65536 entries per mapblock
that can fill a 90x90 map(block) with height 2 and all tiles have different ground/wall(E/W)/object mcd entries (should be enough
)