What Color Working Space for Feature Film VFX Done In IPP2?

I would use the practices here as my guide and choose a workflow that suits me depending on the comp tasks and post production pipeline. typically for vfx comp work that's more than basic I would use a linear workflow with or without ACES.

https://www.youtube.com/watch?v=lns6AuJzBnI&t

My standard workflow is to work with uncorrected footage as much as possible, use an adjustment layer on top with very simple color correction to double-check the composites and effects for accuracy, then turn it off and render to a visually lossless format to send to the edit so color correction inside the NLE is consistent. Inside the NLE I do 90% of my color correction with an adjustment layer above all of the video tracks that sets the basic look, then additional adjustment layers or color corrections are applied to each shot for the final grade. The choice of color correction that you use to check shots in AE is completely up to you but you must make sure that you are NOT adding any baked-in color correction to the original footage in the shots. This doesn't mean that you don't color correct the other layers in the shot. 

For some types of VFX shots, I'll set the original footage layer as a guide layer and render a DI with transparency so that the composite can be done by just dropping the composite above the original shot in the NLE and fine-tuning the color grade there. I recently did a bunch of TV screen replacement shots for a film and I sent the replacement screen to them so they could perform separate color corrections on the screen and the original footage. The comp looked like this:

But this is what the render looked like, just the replacement TV screen. That gave the colorist the ability to fine-tune both the original shot and the replacement screen. If I had rendered the entire composite and they wanted to remove saturation and add blue to the TV screen the final color grade would have been a lot more difficult.

It is almost always a really bad idea to color correct an After Effects project, then render the shot and add it to a project that is going to need additional color correction. 

When you do the final render for delivery to the editor it is important that you either turn of color management completely or perfectly match the color workflow for everyone else in the team. More than 90% of the time, I have CM turned completely off.

I hope this helps. When I get to my desktop I might be able to post a couple more screenshots to give you a little better idea about the workflow.