Was playing around with splitters and mergers and discovered this tech. Could be useful for compact transport, as well as certain balancer designs... at the cost of blatantly disregarding the laws of physics. May have been discovered already, but I haven't seen major talk of it despite its usefulness.

In case the video wasn't clear, the setup steps are

1. Place a splitter/merger and run your first belt to it as normal.  
2. Dismantle and replace the splitter/merger in the same spot. Ensure that the merger is placed on the ground, not on the belt itself. Nudging the merger into place makes this easy.  
3. Connect the second belt from a separate source to the same face of the splitter/merger, which will now be open.  
4. repeat for each belt you want to overlap  
5. to separate overlapping lines, you can place belts on the ends of the belts as normal. Note that it's nearly impossible to separate any specific belt off, as all of their snapping hitboxes will be on top of each other.

Fused belts like this, if blueprinted, will connect to each other using blueprint auto-connect. you can use that fact to save a ton of time placing and removing splitters/mergers if you use this for long-distance transport.

So this is what cursed knowledge feels like...