Varying the master clock on the AT91SAM7X

I have a special need for one project that requires changing the clock (via PLL) on the AT91SAM7X by ±1% or less while running. I am only using the ethernet peripheral. I have never tried this with an MCU before.

Will this cause stability problems assuming the clock is only varying by 1% in this way? Can this be done live, without switching clock sources? I have other ways of solving this problem but this would actually be pretty simple if it won’t likely cause stability problems.

Does anyone have experience doing anything like this?