I keep a small stash of MJ mixed with SD(plain leaf)@50/50. Typically 2 bong hits, gently smoked is plenty. I tend to use this more for quiet contemplation v socializing. Interesting how the SD brings a subtle profundity to the experience. If one has familiarity with Salvia space, the effects are discernible even at very low doses.
My experience has been that the value in smoking a bit of potent SD extract is more about familiarizing one to Salvia space, than the intense(though interesting) full immersion "Salvia Droid"(hat tip) circus. Indeed the deep, space/time/matter/energy, mind melt afforded by potent extracts CAN bring learning IF you're an individual who is able to "endure" the ordeal. It's not widely enjoyed however.
For many, "reverse tolerance", is a useful characteristic of using SD as an ally. I'll occasionally quid a few plain leaves, post peak, during mushroom or anahuasca trips. It brings an interesting combination of "headiness" and "visceral grounding". Low dose SD lends a queer sensibility of the embeddedness of the body in the reality matrix. It reminds me of the VITAL role our bodies play in allowing us to transceive the Consciousness field in which we subsist AND are, moment to moment, sustained by.
In short, it is the subtle planes of SD space that allow comfortable, ergonomic and fruitful study of mystic experiencing!
Peace