My P07 was easy.
The P09 was a pain. It was very, very tight. I had to work the safeties up/down for a good bit to make them "wear in" to feel like the P07. Worked them with right thumb, then the left thumb, then two thumbs on the left side and finally they got to feeling okay to me.
While not a P07/P09 my second P01 Omega would not work with the safeties when I got it. I grabbed the Urban Gray P01 Omega and swapped the safeties from one to the other and then both guns were fine.
Little bit of clearance, or non-clearance, can be an issue.
Take a look at the fitting/trouble shooting video. It's probably not going to take a lot of metal removal, so go slow and do fit/function checks often to make sure you don't take off too much metal.