AutoTRAX has a fixed grid for schematic terminal magnets, schematic terminals and schematic wires and buses. This is 0.05". This is 1.27 mm.
This was chosen for visibility reasons and to ensure it is easy to lay out wires vertically/horizontally with no small snap compensating section. A unit mm setting such as 1mm is too small and 2mm too large.
The AutoTRAX schematic wire auto-router is grid based and uses a grid of 0.05".