Had an idea and haven't seen a similar mod do this (that or I suck at searching), but would it be possible to have two or more input or output locations for one inserter? IE one Inserter can pick up from a belt on the right or left and drop off into an assembler. Or say pick up from an assembler and drop off to another assembler or a chest. some logistics would have to apply, IE which one gets priority for drop off/pick up.

There's no straight forward way to accomplish this that I know of. So it's not something I'm going to investigate sorry.

You could achieve something similar with two separate inserters. Use the circuit network to disable one or the other.

I think Miniloaders accomplishes what it does by using Inserters to fake the functionality of a loader, and it basically does this by having 2 invisible inserter arms moving items really quickly.

A standard inserter though, I mean, it would need scripts to actually place 2 inserters in the same location, and both sets of arms would need to be visible, so... It's not something I'd want to try and do.