Does Renderosity have any previews or examples of the "Post Render Effects to speed or embellish renders for single frame or animation renders" that was mentioned in their Poser 12 blurb? I'm dying to see what they have up their sleeve. I really hope they do not change or alter the "toon outline" feature in the firefly render engine. I really rely on that for my brand of artwork.

Nothing has been revealed as of yet. We'll have to wait until it gets closer to release date.

I hope it's not just limited to the superfly render engine.

I would expect it is a light postprocessing kit like you have on your phone camera: Some preset filters, effects, cropping, maybe adding a text layer. I purchased CameraBag2 at some point and it helps to add some salt to my rendered images and make them less flat and artificial.

If this can be done in Poser it would save some app hopping but of course if I do this postwork stuff in Poser, Poser will be 'busy' and I likely will not be able to run a render at the same time.

The rationale for a limited postprocessing facility in my phone cam is that I an make images anywhere anytime. The facility allows me to do the edits on the spot. I do not need to wait until I am home and then transfer the images to my pc. Poser images however I make on my pc and specialized apps like Camerabag2 or full PSP are instantly available and more powerful than a Poser plugin feature.

Added value may come with nifty additional dedicated features using Poser's knowledge of what is on the image (a view of a 3d scene), filters tuned for use with render results instead of real photos, or of Poser's knowledge of relations between the images it created and use that for say seamless patching of results of partial renders on a full image rendered before.

Cycles Postprocessing:

https://docs.blender.org/manual/en/2.79/render/post_process/index.html

Cycles' postprocessing strikes as rather technical.

I can imagine they build in some 'gimmick' in this vein: http://opensource.graphics/category/image-processing/.

We'll have lens flare, right?

Is it cool again? It was cool in Photoshop 5.5.

No bloom or lens flares yet as far as I can see, but you can adjust the exposure, saturation and apply denoise

when is Poser 12 for Mac coming out ?

Not sure why you are asking that in this thread, but should be soon. https://www.posersoftware.com/downloads says "Poser 12 for Mac is expected to hit beta by mid-December." Based on that and an announcement they sent out, I would guess they thought it was ready and then caught a bug that was big enough that they needed to fix it first. Pure speculation though.