Re: AP1100 park position question
I have used Park 4 for several years for exactly the roof height issues that you are evaluating. This is for a 1100 mount with a 14 CDK scope. There have been no problems.
I have a PierTech height adjustable pier (http://piertechinc.com/telescope-piers/). When I need to tinker with equipment, I lower the mount and move it to P3, where it clears the roof. To remove equipment, I loosen the clutches (older style 1100) and rotate/lower the OTA to a separate support table before loosening the dovetail. I normally leave the pier at almost max height, in order for the roof to clear on opening.
The adjustable piers are actually from another company, but I have forgotten the name. I think Chris Erickson has these.