Yea, In the past I've always attached the gauge to the regulator itself. So I get what you're saying.It is my understanding that some mount it out of sight because they use a gauge to monitor it; they set the base pressure and then don’t need to mess with it much after that.
I did the traditional mounting by the brake master, however, after setting base pressure I have not needed it since. My mech gauge is on the rail, factory FRPS for MS3, and my Speedhut is in the regulator. View attachment 1879652
I actually mounted mine to the EGR block off plate with my 3.4 car.