The beauty of lever machines for me is its ability to clearly reflect the timing of the shot so adjusting the grind directly changes that timing. With pump machines????

Yes, I second that

Archie, I am trying to be respectful here but forgive me if you are offended, it may save your life. If you are asking these basic questions here you should not be doing this yourself and need to engage an electrician

I always pull a full volume shot but the grind is optimized for it

correct

I haven't tried it but maybe tape the screen and with water in the piston lever pressure may will push it out

Eddy is absolutely right

No, this was standard on early models

There is a solution. First take out any dents you have made. That is make it flat again. Then put a little bend in the disc like folding it a little not too much only bend a say 5mm. you will be able to push it in place then pressure to make it flat and it will go into