Seems that Mantra runs without pre/post-frame/render scripts from Render COP. Is it bug or something else? Sometimes you are lasy to render pics to disk and want to use the Render COP. But in this case you are don't able to use scripts (say for switch takes).
So maybe it's good thing for RFE?

did you try putting a render scirpt on the mantra node that you are referencing from the render COP?

did you try putting a render scirpt on the mantra node that you are referencing from the render COP?

That's what hoknamahm is doing.

The pre frame & post frame scripts are purposefully ignored, because they can do all sorts of nasty things if executed during a cook. ROPs don't cook in the traditional sense, so it's fine to execute them from there.

I agree it's a nice RFE, one that has been requested before.

I agree it's a nice RFE, one that has been requested before.
Very good. Thanks, twod