I feel like I would've been set up better going in blind since probable lie questions would've been real for me and since I have nothing to hide on relevant questions I would've been fine. But now that I know how this works, I feel like I will think I will get more nervous at relevant questions thinking I should keep the response down and then undershoot CMs on control questions. Any advice on calming down on relevant questions now that I know how this works?

Honestly, what's going to calm you down...take all the technology aspect away from you head, your over thinking it.   

Now, next time that polygrapher says, that he's detecting deception through the polygraph.  we know it's BS so replace polygraph with Santa Claus

Santa Clause is detecting that you naughty, 
Santa clause is telling me your lying.   
Santa Clause is giving me some bad readings!
Are you sure you telling me everything (subconsciously forcing you to recall anything) cause Santa Clause is telling me your lying.    

Now you P.O., THERAPYST are tricking you to believe in this crap.  which is causing you paranoia, exactly why they make you believe in Santa Clause, to trick you into falling for it!  Some guys fall for it, and document their daily activities through the day!  This is why therapy tells you to carry a pen and pad with you.   

Now will you really get nervous if Santa Clause ask you if your naughty or nice ?   

Think about it.  Once your realize it's just a scam, it won't affect you.