I don't think you'll have any issues with it, but I'll tell you my experience with using it with the UG filter.
I wasn't going reverse as you will, and I was only using plain aquarium gravel. It worked very well under the gravel and kept the water spotless. The only issue I ever had was that after about a year of use, even with regular vacuuming of the gravel, the poly was so clogged that it would greatly restrict the water flow and need to be replaced. Back in the day that wasn't so much of a problem as it was time consuming. Beneath all that soil, planting and aquascaping it could potentially be a much greater issue.
Since you're going to go reverse, I don't think you'll will experience that situation. You'll only be pushing clean water through it from the return. That being said, I'd hate you be cursing my name a year from now... Best of luck and keep us posted on the outcome.