Overall, I'm still not clear whether one generally wants to be bow light or bow heavy when poling up or down a river, other than you want to be bow light when trying to ascend upstream over a ledge.
Seems like the answer is: "it depends". Thankfully when poling, trim is easily adjusted on the fly by means of hopping.
This is why discussing it will never be as helpful as getting the boat in the water and practicing. Learning by repeated failure is the way. It does depend on a lot of variables, including which boat you're standing in.
I break these bow light/heavy "rules" all the time, depending on the situation. They don't even seem to apply much in hulls like the NC Prospector and MR Guide, in which I pretty much just hang out close behind the yoke or just ahead of the seat, respectively.
Moderate symmetrical rocker kind of makes it irrelevant - but tends to come with a less efficient hull.
And you can easily carry this past the point of diminishing returns. It's good to have all these things in mind, but ultimately, it takes time in the boat pushing your limits (and failing) to drill this into your brain/body. I remember being told years ago by someone on the old P.net - "If you aren't swimming, you aren't learning".