Christmas came early!
Nice going Graham. Great tracking, nice & sharp. Lots of detail visible.
Matter of taste, but maybe ease off a little on the Optimize module - I can see 'Tame' has been given (too much?) free reign to enhance detail and optimise dynamic range. It's given Eta a slight 'gappy' appearance at places, though, I have to say, those 'gaps' are actually real darker detail (not artifacts), so it's all subjective.
Here's how you can 'tame' Optimize/Tame a little. Just Optimize as normal, then, when you're done, launch the Layer module. Click Undo->Fg and just blend between the Optimized image and the non-Optimized image.
Edit: Added a more boring repro...
Cheers,