Hey there,
in the vanillamode is the function that the fast inserters need the previous inserter of the lane, to get upgraded. I like this because, u dont produce so much garbage in the first. Because at now in ur mod u build the yellow ones, but if u switch to the fast inserters u just can put the slow inserters into the crushing mashine. I would prefer, that u can upgrade any of the inserters, also including the burning inserters, that needs maybe the automatism core to get it electrical.
And maybe also an new item to upgrade an fast inserter to an filter inserter, maybe an laser dector, that scans the item, so make it little realistic :D
And the other aspect is why it should be inside the mod. The loader and stuff also needs the previous version to upgrade them :)
Greetz and thx for this awesome Mod
Santa :)