Imagine situation that you are trying to build dense industrial region with interconnections between factories to produce some soviet microelectronics - the biggest microelectronics of the world. You trying to place buildings in the most optimal way to be able deliver workers and build factory connections. Looks like you've figured out how to place buildings
But after buildings are placed, you can't put factorial connections. Some angels are too sharp, some ways too long, and there are to little of the points, where connection could starts.

Fortunately, such thing as wall can't stand on the way of the planned economy!

As @JonahF2014 mentioned in comments, it will be good idea to backup the media_soviet folder.

Navigate to the /SovietRepublic/media_soviet/buildings_types/, there are several *.ini files.
Open mechanical_components_factory.ini and add lines

like in screenshoot below

This will create 3 additional connections. CONNECTION_CONNECTION means that type of the point is factory connection it could also be CONNECTION_ROAD, CONNECTION_PEDESTRIAN, CONNECTION_RAIL_ALLOWPASS, etc. Numbers are coordinates, zero at the meedle seems to be the height of the connection point.

I've also added 3 connections to the electronic components factory:

Now industrial ares seems to be fine, and my workers are ready to start wasting precious resources to produce unreliable and outdated soviet electronics.

Also, warehouse storage limit is unsatisfactory low, but fortunately, as first secretary of the communist party you could just decree to storage more. To do it, navigate to the warehouse_covered_combined.ini at the same folder and set bigger storage limit
This will affect only new buildings, that are placed after changes applied.

Let see, how resource production is balanced. Navigate to the SovietRepublic/media_soviet/buildings_types/eletronic_factory.ini and you'lee see

Will it work, if we will produce 1 ton of electronics from same amount of the ecomponents, plastic and mcomponents? Yes, it will work, but such defective electronics will cost like dirt, so even it transportation to the border will not pay off. Price of the goods is evaluated dynamically based on amount of resources and efforts spent to produce it.

Changes in this section will affect existing buildings.

Number of resources stored in the factory, number of living places in apartments could be changed in the same way, but please keep in mind that editing it too much could ruing gaming experience and could cause bug or crushes. I'm quite sure that Peter will not be happy if you will ask for support of modified game, so please, do changes in reasonable way and be careful.

Carry on, comrades.