Did the 7424XP come with a hook and loop backing plate and which size 5" or 6"?
I think that originaly it comes with a white pad that has an intergrated backing plate. But if you can use the CG Hex-logic pads on the XP polisher you can use the any pads with it basicly.
I go from recommendation that you want to have a 5" backing plate on the XP polisher and any 8mm DA polisher. With these type of polishers a smaller backing plate and pad rotates fast which means easier to keeping the pad spinning. To see this you mark your backing plate with a sharpie I think you call it. Then while you are polishing you will see when the pad is stalling. If it does stall it won't correcting any. One more thing that's a benefit with XP polisher and any 8mm DA polisher is that you can have a 3" backing plate on too. This can be handy to have when you polishing the a-pillars and other smaller places. Instead of buying a dedicated 3" polisher this is an awesome option to have. Just put the speed setting down 1-2 steps as it rotates even faster and easier with this on. With the 5" backing plate on you will be able to polishing faster as it's that of a difference to a 6" backing plate on it. Even on the stronger Griots Garage 6" polisher it's recommended to have a 5" backing plate on it to be more effective and not to bogg down and stalling as easy. Another benefit with the 5" backing plate is that the pads is slightly cheaper to them than 6". And that's welcome when you need a lot of them when you are going to polishing the vehical in one day.
If you don't have the 5" backing plate here are the links to them. Others can maybe chaim in which brands they like on the backing plate.
Porter Cable 7424 Backing Plates- Dual Action Hook & Loop backing plate for your porter cable 7424, The best backing plates for the Porter Cable 7424
Griots Garage 5 Inch Vented Orbital Backing Plate
Griots Garage 3 inch HD Backing Plate
And the pads.
Lake Country 5 1/2 x 7/8 inch Beveled Edge Foam Pads, buffing pads, Lake Country curved edge pads, polishing pads
Lake Country ThinPro Foam Pad System 5.5 Inch
https://www.autogeek.net/griots-boss-5-inch-pads.html
https://www.autogeek.net/griots-garage-boss-3-inch-pads.html