Actually, what is your argument against comments on individual combinators? Quoting your post on the first thread you linked:
I am against the possibility of leaving comments on individual combinators.
However, I am strongly in favor of the possibility of placing signposts with notes next to entire combinator setups. When you click that signpost, it will display a message left behind by the person who created the combinator setup. This is important for multiplayer, if you want to have several people working on combinator setups.
These signposts would also be useful for other purposes.
So, you are against them, and you prefer signs. I don't want to sound rude, but I really don't get your point! Please note, so far I have never played Factorio in multiplayer mode. I could imagine that in MP you could only see the settings of your own combinators, assemblers etc., not that of other players -- however, for some reason you could read what others wrote on a signpost. If that really should be the case I can at least partly understand your reservations.
Nevertheless, I wouldn't condemn per-combinator-comments outright. Don't you think that they could exist together with signposts? Consider, please, the following analogy:
A typical, well-documented script (I'm not a programmer, really, but I have cobbled together a couple of shell scripts in the past) should state the purpose it should be used for right at the top, possibly together with a summary of allowed options, copyleft notes etc. Then you typically define a bunch of functions. If it is not already obvious from the function name, you add a comment above or at the start of a function explaining what it is used for. Finally, you add comments to singular blocks of code, or even to single lines, so you will remember why one loop starts at zero or to emphasize that you are using a global instead of a local variable.
In Factorio terms, you could use bricks, concrete, colored landfills, textplates etc. to describe what you want to do in a particular area. When planning your factory, you could use such markers (i.e. comments) for a rough layout (something like "Smelter", "Stacker", "Science production" etc.). If the letters are big enough you could even see them in map view, so you get a rough idea how everything is laid out. That would correspond to the boiler plate comments on top of a script.
Then you could use signposts inside such an area to describe what a certain group of combinators is used for. At a train stop, for example, I could have one group of combinators to determine when a green signal is sent to a train (e.g. if an empty train arrives at an unloading station, if the train doesn't have the required cargo, if there is no space left to unload anything, or if some time has passed). Another group of combinators could be used to request a train with a specific cargo, yet another for processing what other cargo a train is carrying in addition to the material needed at that station. It would totally make sense to use signposts to summarize what a certain set of combinators is supposed to do (given you still have the place to cram a sign in, which I unfortunately don't have in some stations). The signposts would correspond to comments for a complete function.
Finally, when you get down to the nitty-gritty details, there would be the per-combinator-comments that explain what a particular combinator does or what meaning you have assigned to a particular virtual signal. That would be your per-line-comments in a script.
I believe there are legitimate use cases for all three types of commenting -- i.e. using floor decorations, signposts, and comments on individual entities. So, without wanting to sound rude, what exactly is your argument against the latter aside from "I am against it"? If you really don't like comments on combinators, just don't use them, but your being even "against the possibility of leaving comments on individual combinators" is something I just don't understand. After all, having different options/possibilities to do things is just what Factorio is all about, I thought. So if there are any
real reasons against using per-combinator-comments, please explain -- I would give way to good arguments, but it takes more than a simple "I don't like them" to convince me.