The Vive Pro 2 offers a nice bump in FOV, especially horizontally. When you first put it on though, it won’t feel like that. Especially when you are coming from the Valve Index! Because vertically, actually you will have less FOV than with the Valve Index. And you won’t feel that you have more horizontally, the first thing you will feel is that you have less vertically. It is just how we perceive things.
Good thing: there is a really simple fix! Simply exchange the facepad! The original facepad that comes with the Vive Pro 2 is pretty thick. Your eyes can get way closer to the lenses and therefore gain so much more FOV! I recommend the following thin Facepad from VR Cover: XG Cool Foam Pad. You get it here: US-Link, EU-Link, International-Link.
It is actually for Oculus Quest 2, but it fits perfectly, is very thin, incorporates a cooling gel that will make playing more comfortable and there is no light leakage when using it. The website says you would need the VR Facial Interface kit, but for this mod, you will not need it because the Pro 2 already offers the velcro to attach it to!
I hope you enjoy this simple yet effective mod!