it seems to consume a huge amount of update time when it's updated on every tick.

getting Inventory is more expensive than getting empty slot count.

you could at the minimum, make the mod configurable so that the interval and number of supported cargo wagons can be defined by the player.

I can add some performance options, it may take some time. Honestly this mod is more of a prototype/toy. Thank you for trying out the mod though!

LTN or Inventory Sensor should be better in every respect. The reason I wasn't using get_contents is because it's not perfect: one could have partial empty stacks, which messes with counts of empty spaces.

Inventory Sensor scans for manual wagons (and tons of other unnecessary things) and is much worse for performance.

Sorry it took so long. I uploaded a 1.1 version with tweaks, but it should be back-compatible with 1.0 (I could upload an update for 1.0)

If there are any bugs, I should be available to fix them, today

for now i have come up with a workaround just filling up a chest and connecting it to a circuit network instead of reading wagon contents. this is computationally more expensive than doing nothing but the map must function! it's cheaper than the lua was. i'll look at the changes you made sometime, though. thanks Honktown