It's pretty well established that the current iteration is a bit...rough, but I'm actually in the camp that likes the messy behemoth that's hiding underneath. The issue is that it's currently frustratingly tedious to untangle that mess.
Currently, you can right click on any tech displayed in the tech tree and get a truncated picture of the tree that shows both every prerequisite that the tech requires as well as every potential future tech that relies on it as a prerequisite. The problem, however, is that if you want examine another tech further down the line, you have to exit the truncated window, search for the tech via the search bar in the main tech tree window, and then right click on the tech. With the added bonus of a significant amount of lag between every window transition. Even without the lag, however, the process is unwieldy and should be refined.
My suggestion here is quite simple: Allow us to right click on another technology while already viewing a different tech's truncated view. This would go a long way towards making it easier for the player to untangle the tech tree without compromising the interdependencies that make it stand out from most other games.
Another change I'd like to see would be to make the "Full tech tree" button a toggle called "Show engineering projects" or just "Show projects" and make it available on both the main and truncated trees. That suggestion, however, is less important and has more potential issues with existing UI programming.