First off - congrats on your build
Secondly - its really NOT
my intention to put a downer on your project..,
I will be using the floating adapter plate method using 3/4 stainless hardware from Dan's Pier Plates. There will also be some rebar installed through the entire pier length and into the ground below.
Adjustable top pier plates is indeed the way to go - which is what most folks are using.
Whilst I'm not advocating your stopping / changing your intended plans, I'd be looking to consider: -
a] Settlement that causes pier shift effectively results in a vacuum created on the opposite side of the shift direction
b] Once pier-shift starts, there's really little means of knowing WHEN
it will stop
c] A pier that has shifted will also result in the center of gravity of your load also moving away from the previous center
d] In addition to [c], the weight at the mount will, as a matter of course, be exponentially increased towards the direction of the shift - think of why you move counter-weights along the counterweight shaft to balance a GEM, so the greater the angle of shift, the higher the resulting effective weight will be at the mount
Just bits to consider.., that's all.
Best wishes with the build..,