I am not sure how often the gates are reset for precisely what levels are available in them, but would someone who has experience with them be able to generate a wiki or sticky breakdown of what each level is?
For example, right now there is a gate with Iron Edge Arena: Robo Rampage available on the first level. In here there are lots of turrets and robot enemies, which I have found to have a high droprate for blue shards. Later in the same set is Deconstruction Zone: Savage Salvaging, which has lots of gremlins, and I assume that means a chance to drop the Gremlin Gizmo (have gotten 1 from one of them, but in a deeper level).
Having some knowledge about the levels, even just "Lots of Spike Traps," "Mostly Wolver Enemies," "No Gem Supply Location" or "Contains an optional Boss Gate" would be really nice. Having a "High chance of Blue Shards/Gizmos/Whatever" as well would be awesome.
Just seems like it ought to be possible to compile, and have available so that you can make the most out of your trips into the dungeon by choosing a route likely to yield what you need.
The levels don't stay the same. The path down changes quite often and has many variables. It's easier for you to understand how to read the gate map and figure out the best path from there. Which would be easier to make a wiki article about.