I have a Marauder Pistol so things may not be exactly the same but I think they are similar. I tuned mine to increase power and shot count (it only has 66cc of air storage). On mine, the hammer throw did not seem to do much until I did a Bstaley tune (O-rings around the valve stem). The Bstaley flattens the velocity curve and gives you more shots but hammer spring tension has to be turned up to get back to the same velocity. I had to put in a stiffer spring.
But the first step is to fill it to fairly high pressure, something over 2500, and then measure velocity of each shot and pressure every 5 shots or so. You want to figure out what pressure to fill to. For me it was about 2500 for the stock tune. Filling to 3000 gave more shots but they were low velocity shots. You have to decide how much velocity variation is too much and that will determine your starting and ending points. You will need to know your hammer spring setting for the shot string.
If you don't like the power, you can increase the hammer spring tension and see what that gives you. Again you have to shoot a string to know. If hammer spring alone is unsatisfactory, you can try a bigger transfer port. I bought a few from Crosman (they were cheap) so I could go backward if I wanted. Then I drilled them out and did more strings. The data somebody provided may help you better plan where you want to go. But you will still need to shoot a string to make sure you got there.
Not sure what sort of chrony you are using but I really like the inexpensive chinese ones that don't use visible light. About $30. My favorite is made for tripod mounting so it doesn't affect the zero at all. I can test pellets for accuracy and/or zero the scope and get my shot string data at the same time.
I recommend finding a pellet that it likes and then tuning the gun to give it 800-900 fps. I would not worry about the fpe too much. I've had great luck killing squirrels with my Prod tuned to about 18 fpe. 25 would be plenty. But if your gun likes heavier pellets you power would be higher (or your trajectory will be steeper). I use H&N FTT copper plated in my Prod but it also shoots Crosman 14.3s well. They work great for pesting. At 25fpe with 14.3s a lot of your shots are going to go completely through squirrels at 25-30 yards.
I would get a tune without the Bstaley and then decide if you want to reduce the SD and extend the shot count a little. You may be happy without it. It is not terribly hard to do but the O-rings mean you will have to mess with hammer throw so there is another variable to test and optimize. Every time I increased the size of the transfer port I did a series of shot strings with different hammer spring tension to optimize accuracy, velocity, and shot count.
