I guess the last two posts better phrased my question and gave me the answer I was looking for.? I understand Murphy's Law and personally I think that Murphy was an optimist.
I really have two goals which both lead to the same place.? I want the best PE I han achieve which will lead to the best image shooting available from my mount.? The resultant images are, of course up to me.
Thanks to all.? I shall proceed slowly and just record the PE for each change over time.
Pete