I have a new hydraulic place diverter and was interested in possibly installing a trim gauge for it. I read through some old posts on here from 2010 about the hydraulic PD having a potentiometer that you can somehow tap into on the hydraulic pump and use a standard trim gauge vs the expensive pre-made/external kit sold on CP/berkely.

Is this possible, if so how (pictures)?

So basically you are saying just go by feel of the boat or turn around rather than relying on a trim gauge? I understand spraying a rooster is all show. I am more concerned about over-driving the hydraulics too far up or down because the trim is already at max setting and I click the switch to request for more (overdrive) because I don't know the exact position.

You can't over drive the cylinder. The cylinders are basically designed to run full open or full closed, hundreds of thousands of cycles. Remember, they are full of fluid which keeps it lubed and also acts as a shock absorber when it reaches the end of the stroke. As you raise the nozzle you will feel an increase in speed. Once you feel the increase stop you will know that you are there. The actual run time from full down to full up is only maybe 3-4 seconds. I worst comes to worst, have someone in the boat with you and time the full up cycle. You can always look over your shoulder and see where your stream is.