By no means can anyone claim that RC prints exhibit the same life expectancy as properly processed and framed fiber based prints. For most people, such performance is not a concern.
My reason for using selenium on my RC is for a bit of deepening of the paper's Dmax and that slight shift toward a cooler somewhat purplish hue. I can see that on fb paper that I've printed before. Since getting my darkroom going again I'm using just RC as I get back into the swing of things with printing, and so I want that same look with RC, maybe it's not possible. I toned an RC print in selenium 1+7 over the weekend but not much change, that's why I was wondering if a stronger solution would benefit, I'll try 1+3 as someone previously stated. Any longevity benefit would be a bonus.