So this script basically lets the player carry more than one part at a time in tranzit
https://www.mediafire.com/file/dj5l0ekveiz7a2s/zm_transit_multi_carry.gsc/file
Make sure to install the script in "%localappdata%\Plutonium\storage\t6\raw\scripts\zm\zm_transit"
if there isn't a folder named zm_transit creat one and place the file there.
Haven't tested it on co-op