Top, right, left, and bottom functions, at least in the red/green functions, seem to work very inconsistently in my save. Being confined to "this" itself creates some problems where a combinator may react to its own output, especially at low tick rate, which can render it unresponsive to outside stimulus.

Can you please provide a concrete example or save where it is working inconsistently? I need to be able to reproduce this issue somehow in order to help out.

Thanks for the very prompt reply.

This is far from a minimal example, but my current save can be obtained at https://we.tl/t-e4YuksCSec You can see the general coordinates of the combinators in question in the chat, they are around 1000,200. You can compare the combinator at the top of the array, which detects the lighted medium pole signal on the top and thus emits a lighted medium pole signal. The combinator at the bottom right of the array seems to fail to read the transport belt signal on the right and thus doesn't emit a transport belt signal (or any signal for that matter).

However I think I have now narrowed the problem down to the use of the lighted power poles from Lighted Poles Plus. Somehow your functions read them as having no signal data in them. When I tried to make a minimal example I failed to check that I was still using lighted poles, which seems to explain the problem. Not sure whether you can fix that, though. In any case I was able to get my use case to work the way I expected now by just reading from vanilla power poles.