Optimizing my LTN stations.

Hello fellow factorians!

I'm growing to love LTN and I'm trying to make it better by using various circuit networks magics, but I'd like some of your tips on how you optimized your LTN stations (both provider and requesters)

A Couple of notes first :

• I'm playing with Bob & Angel
• I'm at the beginning stages of setting up my train network, so I do not have clean-up stations for every materials yet. Therefore, it's common, for now, to have trains come back with half-cargo from previous-failed deliveries.
• In addition, since I'm at the beginning of setting up my stations, it will happen that some stations will produce but there products are not being consumed by another station yet, so belt bottlenecks will occur.
• My train setup will mostly be 2-8 going one way.
• I did not even get to the Liquid station yet.

Here's a few areas I'm struggling with :

• How do you make your Requester stations ONLY issue a request when there is enough room in the chests to unload every wagon of a train? (Request threshold works for the whole train, not individual wagons)
• The 'total time elapsed' condition on for trains to depart is a hit or miss I find. I'd love to find a solution to better fine-tune the train departure system. I read that when a specific option is enabled, we can send a "green" signal that will tell the train to depart. Now, this is interesting, but can get complicated very quickly. For example, without LTN, I had my trains setup with the following conditions before they could depart
  Provider station : Cargo is full OR Chests are empty OR 5 seconds of inactivity
  Requester stations : Cargo is empty OR chests are full OR 5 seconds of inactivity
  This system was easy considering the fact that I could control which train had which materials. But, with LTN, I don't have as much control over which train comes to my station. Some of them may come in to my requester stations with unwanted materials. So, I would like to find a way to tell LTN that the train can go if the chests are full OR if the train no longer have any of the requested material OR if there's still room in the chests, but the remain cargo is not the material I want.

So, what about you? What are your favorite setup for optimizing your LTN stations? Anything else I may be missing?