@Baggins
Yup, I can just picture you now, relaxing in some fancy hotel with a pretty maid tending to your every need.
Girls in Wickedweasel bikinis beside the pool, serving you cocktails!

You can't tell me that's more attractive to you than starting work on BB_Anamorphic :-D

Anyway, from my limited understanding of the Poser Material Nodes, and zero understanding of Poser Python, I get the feeling it can be done but it would not be ideal.  I sort of know from stuff you've shown before, that Anamorphic lens flares can be done using the material nodes.  But to be honest, I'm personally not that bothered about the flares, it's the vertically stretched Anamorphic blur I'm after.

To do that, I get the feeling it would have to be done using Poser Python.  Unfortunately, we can't stretch the virtual film plane, and it's a shame because I think that would be the easiest and best way to do it if it could be done.  What can be done, though (just guessing), is a little math in a script which basically stretches every object in the scene, but most important, the stretch of all objects is always on the camera plane axis.  Like I said, just guessing, but I reckon that might at least be possible.

BTW, here's the thread if you're curious, see how the Octane dev went about it, and knowing you and your nodes, you might be able to do the same thing with the Poser Material Nodes.  You'll notice the Octane dev was confused about Anamorphics at first, but after another explanation, he came good.  I was surprised to see him implement it in the way he did, in fact I didn't think it would work at first, but then a member posted a test which shows that it does!

So there's at least three ways to implement it, I'm just not sure Poser has the suitable 'probes' for you to get at such things.  But anyway, I'm drailing your thread here so I'll leave you with the thought of "BB_Anamorphic" - it would be cool so hope you have a go at it :-)

Get the maid to bring you another cocktail, then have a nice relaxing read of the thread.
Click Here for Octane Anamorphic thread (it's only three short pages).