Ok, I did it for me on my own to get it working just right now.
If you want this to, simple do the following:
1) Open the File: Factorissimo2_2.5.2.zip\Factorissimo2\connections\belt.lua
2) Add in line 4 "loader-1x1" so that it looks nowlike this: Belt.entity_types = {"transport-belt", "underground-belt", "loader-1x1"}
3) Add in INSERT_POS (line 20) the following: ["loader-1x1"] = 0.75, -- 1 - 8/32 <<< this is the same value for the transport-belt because the loaders, so I think, are belts with the posibility to extract and import items and it's working fine :)
4) go into line 32, function "get_conn_facing" and as "elseif" the follwing part for "outside_dir" and "inside_dir":
elseif ot == "loader-1x1" then
outside_dir = outside_entity.direction
end
elseif it == "loader-1x1" then
inside_dir = inside_entity.direction
end
I suggest to add it after the "underground-belt" instructions.
Now save the file and overwrite it in the ZIP. You could also extract the hole Folder, edit the file and replace the zip-file with the extracted and modified version. Now reload your game, place down some loaders and have fun seeing it working :)
If you expect any problems with this, revert the changes and let me know it but for now there are no problems with this addition :)