I think the topic speaks for itself. Personally, I’ve had situations where using “Add” nodes with multiple inputs would have made the code more attractive than, say, three “Add” nodes. I doubt I’m the only one who has ever thought about this, which is why I’m asking. I think there might be gurus who know something about this.
For example, “Blueprints” have had multi-input nodes like “Add” for ages, although there seems to be no tendency towards adding this feature to the Material Editor, so I guess it was intentional, although I’m not sure why. Perhaps it’s done this way for the performance, or it’s just that no one has asked to add because it is not that useful. Although performance reason don’t make sense to me, since using one node should be even more performant than using a bunch of nodes (or at least provide the same level of performance).
I also thought that it might just be a system limitation, so I decided to try to make an “Add” node myself. But overall, everything turned out to be quite simple, that is what I got after a day of work:
So that is not the reason.