Shoot whatever you want as long as the weight of the arrow is above the recommended minimum for that particular bow. Also make sure your chosen arrows have the correct nocks, flat or moon.
The Red Hot stuff from Parker is top notch though. If they are shooting that good, not sure I would mess around with it though.
A perfect answer. I am on Parkers field staff and alot of guys don't realize there is a reason that we want you to shoot parker and red hott bolts. These are the bolts that we have specifically engineered to be best with your parker crossbow. Now every Parker Crossbow has a sticker on the limbs that says use only parker bolts. One may ask why? The reason is that it creates a standard for us where we know our customers are shooting the proper length bolt and the proper nock. Parker crossbows are not intended to be shot with flat nock bolts. You have no idea how many guys despite it being written all over the crossbow now and the owners manual want to shoot flat nocks. If you know what you are doing you absolutely 100 percent could build your own bolt and have it shoot awesome. Arrowhead knows what he is doing and it's obvious based on the reviews on this site that methods are tried and true. If everyone tried to build their own bolts like Arrowhead without knowing what they are doing Parker would be replacing alot of crossbows unessecarily. Welcome to the Parker family by the way!
Luck is what happens when preparation meets opportunity