sillyfly, I think you're close to right about it being about form factor and commonality in construction. However, based on that criteria, making inserters fast replaceable with other inserters makes perfect sense due to the nature of their construction.

While in the common and most frequent cases ...

Man, I was looking through all the mods to make sure it didn't exist, I must have missed that one.

Still think it should be a core feature though- the mod has to hack it in via different item types, which explodes the number of inserters (burner, regular, fast, long, smart = 5 -> 15 with the ...

Something that struck me as a little silly and inflexible is how inserters, despite the fact they seem fully capable of swinging in a full circle, can only take and place from in front/behind and move things in a straight line.

At first, I thought what's really missing is a half-turn type of ...