Too much slop is an incredible problem. Before I got rid of the last CMC jackplate (which i thought worked fine), I stood behind the boat while someone ran it up and down and I don't want to tell you how much the propshaft moved left and right. Let's just call it: TOO MUCH. My advice, lose the hydraulic jackplate and bolt everything properly. If you think you're too low or too high, take the boat out of the water or just stop and adjust it. This is all with no mention of the possibility of adjusting it up too high while you're running. You may just 'go around' faster than you want. I and others will tell you where this will lead you. (Can you spell dirty shorts at best or ER???)
Bottom line: If you spend all year on your setup and the drive point is moving around, you've wasted pretty much all year from a setup standpoint. My opinion only, of course.. :same ole song