To get an initial reading I am going to take a 12' x 6' ply board and set at varying heights(angles)then record the % relative to height.
And you want to do this every time you apply power to it?
I thought once built I could time the actuators under load and use the results to alter the program.
That will not work because you will not be able to measure the time / position accurately enough. Also you will find that the displacement of the actuators vs the time they are on is not a liner relationship.