I have no definitive thoughts, but some experience with PAL and SECAM.
If the video switching merely passes along whatever is input and does not do any video processing, such as re-inserting video sync signals, whatever goes in comes out. This would be true for any video standard as long as that standard did not exceed the bandwidth of the video switching electronics. Since it is up to your television to interpret the incoming signal and display the appropriate number of video frames per second, scan lines and color/colour rendition, this would work well.
If there is only minor processing, such as adding a black-and-white only On-Screen-Display of menu items for audio adjustments, you will also likely be OK if the video Character Generator can lock to a frame rate of 25 as well as 30. Most of the OSD CG units I have seen can do this. The difference one sees is that the lettering in NTSC appears taller than in PAL, for instance. This is because a character that might be 50 video lines tall out of 525 lines in NTSC is still 50 lines tall when placed on top of standard European PAL, but out of a total of 625 lines.
What if the menu also adds a color background or colored lettering in some instances? Mostly I have seen that if the CG chip is locking to the sync of the luminance portion of the signal being passed through, but the color signal is not of the type the monitor is expecting, such as NTSC color signals on top of standard PAL sync, the monitor may either default to black-and-white while the menu is being displayed, or the menu colors may show color streaking or flashing while the black-and-white portion of the image is still properly displayed.
Of course all these factors depend on how video is switched/processed in the receiver or pre/pro, and how the monitor handles color information that does not necessarily agree with the format the monitor recognizes by the incoming sync signals.
The only way your going to know exactly what happens in your situation is to try. The shipping cost on a unit such as the Outlaw 950 pre/pro is small enough that it’s probably worth a 30-day, money back trial to find out. Shipping a receiver back and forth would cost more, but then driving to pick one up locally, and potentially returning it, also costs you something.