Keyframe or Cues - enlighten me

It came up on exactly 1 somewhat unrelated thread (that I'm aware of, and I'm probably the only one talking about it), as a solution to persistent marking problems, and then I started a new thread myself that didn't get interaction. So not exactly spamming. 

Once I get keyframes working for Eos, I'll probably post a demonstration here. It'll probably be working by the weekend. 

Basically it's for mapping complex movement to predefined, custom paths. Exclusively for working with a Visual Lighting Sequencer. That I already have working. 

It's like do you want to have ridiculously fine control over interpolations using a massive graph editor? Do you want a dope sheet? Do you want to visually see your entire time-coded light design in 2 dimensions on the screen instead of cuelist form? And do you want that for Eos? I've got you. 

You only came up with it recently. There where other people who talked about it in the past.
And yes, it was not realy spamming. But the opening of the reference thread was something complete different and than this topic took, kind of, over.

And non the less, i don't realy understand the concept or way of thinking over all.
So maybe it can be re-explained to me again, please.