After about 100 or so full-power loads (slugs, 00 Buck, etc.) just to get the action broken in, and in conjunction with the light (red) gas piston installed, it will run anything low recoil, as well as #8 bird shot loads.
To answer your question directly, I haven't used Low recoil Buck in my FN SLP MK.
But I have fired hundreds of rounds of light weight birdshot during 3 Gun matches without incident using the light weight gas piston. It has also served me well in one high round course in the heat and the dirt.
The shotgun gets hot and dirty but I run it wet, just like my AR's and it functions flawlessly.
It is completely unlike my M1 Super 90, which If I didn't hold it tightly or used low recoil loads, didn't cycle reliably.
Use this shotty with confidence.