Thank you Jahe for your suggestions. I have had my Blackbird OC for about 2years in a rotation of 7 other razors. In that time I have used many different blades including Feathers and Bic. I have read as have you the many suggestions for a steep angle and a resulting smooth shave. I have never experienced a smooth steep angled shave with the OC plate. Going to a neutral/shallow angle reduced the scratching, but never went to what I would consider smooth. This is probably a result of the blade forward design along with a small gap narrowing the angle.Thank you @Cannon Cocker for sharing your impressions. That's a pity your results were subpar.
But maybe consider switching blades. I realised I'm getting smooth / excellent results with the Blackbird OC whenever I load a very sharp blade (say Feather, BIC Platinum Chrome). Whilst most users swear on a steep angle I prefer a more shallow/neutral angle. It's a YMMV thing but for me the different angle avoids any significant scratchiness from the comb's teeth.
The Personna Platinum Chrome blades didn't work for me in this razor. IMO the PIR is a super solid and smooth blade but in terms of sharpness it is a "middle of the road" one only. That's why many favour this blade. I do, too - but not when attached to the Blackbird.
I finally ordered a SB base plate to see if that would smooth out the shave. After all most people have that set up and I thought it was worth a try. What I found with the SB plate was a leading edge just as sharp as the OC, but being solid scraped the soap off my face ahead of the blade causing the razor to skip at times.
I will continue to work with both plates in particular with regard to the angle to see if I can smooth out the shave some more.
As I have said the efficiency is stellar, but I want it smoother.