Thanks dave, no I haven't got it working, I've been working on another project today. I'm pretty sure it's the switch node that is causing mr to not recognize any animation. It's weird because it should just evaluate the current situation, not infer anything from the previous frame. I did try keying a random attribute on the same texture node to try to "force" the animation to be recognized, but it didn't work, I'll try another tack soon.
The results are interesting. If I key my custom attribute which drives the offset of the place2Dtexture node via the shading switch, I get these results from the various renders (RV is the render view window):
If I key the noise attribute, to force the renderer to see the animation, I get this:
MR: RV: correct, Batch: Static, only keyed value changes
In other words, the noise attribute is animated, but the offsetV is not.
I tried keying another attribute on the place2Dtexture node itself to see if that made a difference; it did not.