The goal of RHP as in merger is complete and final cessation of separation of that perceived ego-self & entire self-identity back into formlessness, this is why Boddhisatvas who choose to remain separated and incarnate (or on the spiritual planes) having attained the ability to merge formlessly are considered to be making a personal sacrifice, the state of separation per se is considered to be a source of suffering (and often, based in an illusion).
- There is no mastery to retain because nothing will be perceived as being external to the self/Self merger, to BE mastered; nothing exists outside of this. Nor will any desire/aversion, like/dislike, or other dualities of any kind exist.
The Vaishnavite sect within Hinduism (including Hare Kirshna sect most recently) do not generally believe this merger will be total and final, they believe in a more “heaven-like” construct of a separate experience whilst still bathing in and aligned perfectly with the Divine.
I just feel a need as someone who studied this extensively, lived it and walked it for years, to clarify this, to be honest the modern tendency to go “oh yeah bruh all paths are really samey don’t do labels lol it’s all the same thing” are totally ignorant as in, not aware of the practical intentions and often, the effects, of practicing many RHP concepts, specifically that of “detachment” from the world, renouncing the world especially, and ceasing to attach oneself to both the outcomes and manifest forms (including people, concepts of love and personal preferences, etc).
The effects of embarking on a route to RENOUNCE ATTACHMENT to the world are that the world will obey and renounce you back far harder, it will take a while to begin and even longer to stop, so this is a really fucking important thing and almost no-one gets it because they have these muddle-headed newage concepts that nothing is really there and so anything you do will fit any definition you give it, when in reality there is a reason we call this metaPHYSICS - as with the science of physics, certain principles exist in a manner all the wishful thinking in the world cannot stop.
And if you think I’m talking out my ass, you can easily prove me wrong by pouring some barbeque fuel on your foot and setting it alight - if you can quench the flames through thought alone and not even make your skin slightly reddened by this, you are probably able to also defy the principles of metaphysics.
If not, you’re not, simple as that. 
(If a person’s intended meaning when they say LHP is solely “grr demons and gonna be a bit selfish to grab what I want more of check my badassery” then yes of course that’s on the exact same continuum of personal desire etc as “RHP ftw I only work with angels and be holy to create what I want more of” - both of these are also commonly used and deserve to be debunked IMO. Both rely upon perceived desire/aversion, like/dislike, etc.)
And don’t set your fucking feet on fire. Really. 