Thanks for the comments George.
To your points:
I will have to read my 1100GTO manual again about when to polar align. After l I bought my 1100 mount, I was still using the polar alignment procedure that I used for my old 800 mount, and it was not really designed to be able to adjust the altitude or azimuth after the scope and counterweights were attached. The adjustment mechanisms on the 1100 mount are much more robust, and being able to attach everything before polar aligning will make a big improvement to my setup time.
I don't have a permanent pier, but I never set up on grass or dirt either. I have 4X6 treated wood posts buried 18 inches deep into my back yard that have the same footprint as the pier legs. They are level and are immovable. They provide a very stable base for my mount. When I set up this way, the polar alignment is already pretty close. The altitude is almost always spot-on, and I usually only need to make a minor azimuth adjustment.
Using longer bolts makes sense. I will do this immediately. The original bolts were 3/4 inch. I will use the longest bolts I can without bottoming out.
I don't think the mount holes in my pier are oblong. The original pier that came with my 800 mount had only three holes. They were at least 11/32 inch diameter, so there has always been a lot of extra play. I had to drill three additional holes in the pier so I could use all six mounting holes on the 1100 mount.
I really like the idea of a flat pier plate and flat surface adapter. I will definitely consider these, but I don't see the M9010A on the web site.