Usually yes most instances of it come in the first minute but it's also done if I wana keep the death runes for something (keep strong dots on Thok and when I can't keep up use DS), but really other then then that unless you are super (un)lucky with procs combined with BL or such then after the first min or so it doesn't happen much. RC doesn't much change it as using any of the rune Regen talents it happens. There's simply points where you can reach a higher incoming amount of runes/runic then you can use in an efficient manner given your gcd's vs resources