Hi there,
Really appreciate the work you you're putting into this mod :) I just wanted to report a bug that I encountered.
The bug can be reproduced by placing an improved combinator immediately adjacent to another improved combinator (one tile up or down). The ghost entities that represent the input and output nodes of the first combinator disappear and that combinator is no longer useable (since circuit wires cannot be connected to it).
Even more bizarrely, if the first combinator is already wired to, say an electric pole, before the second combinator is placed, the connections shift over to the second combinator rather than getting lost, which perhaps suggests that the ghost I/O nodes of the first combinator somehow transfer over to the second adjacent combinator rather than getting destroyed.
I was able to reproduce it with only Improved Combinator active in a sandbox game. Thanks in advance for looking into this—do let me know if there's anything I can clarify.