Mod to add copy functionality to splitters and more that already exists for inserters <-> assemblers <-> requester-chest.
Goal of this mod is to allow for more smooth copying experience when working with belts. I would be honored if a developer would take it for main game integration.
This mod avoids overriding the default copy behavior, it only adds behaviors. This will change for a 2.0 release, however it will mimic it as close as possible.

Adds copying from and to:
- Inserter
- Storage chest / Requester chest / Buffer chest
- Splitter
- Assembling machine: Recipe input items + fuel input (BioLab). Copying to the machine uses a product recipe search.

Adds copying from:
- Mining drills: Expected resources.
- Furnaces/Recyclers: What it is currently smelting or which resources it accepts.
- Boiler and reactors: Allowed fuels
- Rocket silo: Rocket part recipe
- Cargo landing pad and space platform hub.
- Lab: Science this lab accepts
- Turrets: Ammo the turret can use
- Asteroid Collector: Currently cannot find the filter so it cycles through all asteroid chunks instead.

Click multiple times with SHIFT + Left Mouse button to cycle through the filter list if the filter does not fit, most common for splitters because they have 1 filter slot. Works for splitters, storage chest and inserters.

Planned:
- Copy from/to asteroid collector.
- Hover indication (green and yellow) when a valid copy is available.
- Assembling machine: add an input recipe search.

Planned for a 2.0, overriding copy behavior:
- Assembling machine to assembling machine changes, for example when copying from refinery to BioLab. Default behavior ignores copy if the recipe in assembling machine cannot work on recipient.
- Generalize burning fuel sources for copying, BioLab is most common example, currently requester chest does not request nutrients when you copy from it. Would require a second logistic section that is disabled by default for closest representation.
- Setting for how much time is used when copying to requester chest, default of base-game is 30 seconds. Add this functionality to inserters etc as well.
- Hover copy: Keeping LEFT-mouse+SHIFT pressed and hovering allows in base game to easily copy to multiple machines, mimic and expand this behavior to include all behaviors made.

Release info by version can be found in the FAQ.