Playback problem with the polygon node that uses a tracker.

So, I've been working with some comps that make use of a tracker node. The problem seems to stem from using the tracker to match-move one plate to another(it's a still going behind some GS footage) at the same time that I use it to drive the animation of a polygon node.

What happens is that I will be looking at the original plate with no other elements comped on or effects, and have the polygon node selected, bringing the spline up on the viewport. Again, I'm not looking at a comp, just the original footage with a roto spline overlayed on top as a preview. This results in the playback slowing to a crawl as every node also connected to the tracker also has to render(defocus, film grain, resize, transform, etc.) Sometimes it's not so bad, but does cause the roto to lag behind the playback.

I've managed to find a workaround by duplicating the tracker so that there is one for the comp, and one to drive the roto.

While this is not a huge problem, it is a bit annoying and inefficient. Also, Fusion should be able to tell that you aren't looking at the comp and turn off rendering for the other nodes. Is this a problem that BMD have to fix or is there something I can do to iron this out?

You are controlling the Polygon with a Tracker, but are surprised when the tracker has to process? How else would it control the Polygon?

Also, Fusion should be able to tell that you aren't looking at the comp and turn off rendering for the other nodes. Is this a problem that BMD have to fix or is there something I can do to iron this out?

Next time the tranport controls, there is a series of buttons.
The last one is 'some' 'none' or 'all'

some: renders only what is visible
None: turns off all rendering and updates (good for organizing, or setting a lot of keys that you know the value of)
ALL: render everything regardless of what's being viewed.

In general, fusion does not perform well when poly's are selected.
What I do instead, is use the poly on a white bg, and then use a bitmap to track that in.
There are numerous advantages to that, (and some disadvantages)

You are controlling the Polygon with a Tracker, but are surprised when the tracker has to process? How else would it control the Polygon?

Well, it only needs the animation information from the tracker, why would it need to render all of the nodes plugged into the Foreground input? It works just fine without anything plugged into Foreground, so clearly that information is not needed to drive the polygon's animation.

Also, Fusion should be able to tell that you aren't looking at the comp and turn off rendering for the other nodes. Is this a problem that BMD have to fix or is there something I can do to iron this out?

Next time the tranport controls, there is a series of buttons.
The last one is 'some' 'none' or 'all'

some: renders only what is visible
None: turns off all rendering and updates (good for organizing, or setting a lot of keys that you know the value of)
ALL: render everything regardless of what's being viewed.

In general, fusion does not perform well when poly's are selected.
What I do instead, is use the poly on a white bg, and then use a bitmap to track that in.
There are numerous advantages to that, (and some disadvantages)

I'm aware of this and it was the first thing I tried to change to fix the problem, but it doesn't change it. It looks like Fusion believes that it needs to render those nodes to show me what I'm looking at, despite the fact that it shouldn't.

Can you post your comp here?