this suggestion is for spidertron docks to have an option to mimick the behavior of train stops "read stopped train"
seems like there could be lots of fun ideas, much like the experience with trains.

extended ramble:
I just want to disable filter inserters being used as spidertron loaders from queueing items when the spider is not present. So a true/false one or zero would work for me, but if each spidertron had a unique ID# like trains then it could probably be used for all sorts of things.

as a workaround i may just evaluate for any non-empty inventory and that will probably be 99% reliable.

a possible workaround for IDs could involve having some stack of dummy items in spidertron inventory, require some care setting up unloader inserters to not touch them.