hi there!! this is what i have found out for me:
if You want a lead sound with more edge than the rhythm (which i personnaly dont find always useful) RRB is cooool. RRB adds edge, or ,treble.
if You want to taylor the EQ of that boosted lead sound, i strongly recommend the SBEQ.
(i'm talkin both boost pedals at the end of the chain of course...RRB in front of an OD is a totally differnt story)
i , for years , have used HBOD as solo boost at the end of the chain. either for lightly overdriven lead, or after the DRD for screaming lead:-) i did this with a Suhr Tele and achieved great results. if You add a fuzz at the beginning of the chain, then, with the extra option of running THAT into the HB, You have a wide array of sounds covered
the new MP "light" overdrive should also be great for this.
but the setup i'm talkin about is for a fairly clean clean , loud amp, like a twin or 50W marshall to start with. if Your amp sound is semi dirty already, i guess a whole different approach would apply.