Is the whole notion of a vacation life on Earth really a non-starter? Like someone suggesting a six-month stay in a prison is a vacation? Is the need for a vacation truly met with the time in the light between incarnations, or is there a genuine need for an occasional easy and fun incarnation to balance things out a bit? Are there such things as vacation lives?

This is very much the case. For many reasons, there may need to be a time of recuperation, of rest, and this is often best done back in the earth plane because it is while one is in the earth plane and feeling the dense energies that one is triggered by their karma to re-experience negativity, to struggle, to suffer, and to have the increased burdens that may have impaired their lives markedly before. If there is a great danger of that happening again then it is a question of diminishing returns to come back in a series of lifetimes only to fail and compound the damage such that there is a decreased likelihood of being effective or even surviving if repeated too many times in a row. Coming in for a "vacation life," as you call it, we would call simply a "time-out," a restoration opportunity to be back in the density of the physical, having some karmic rumblings, but being largely shielded from the Law of Karma impinging too greatly in a way that could knock a person off balance and lead them into a series of failures impossible to recover from. Having a time to relax, be relatively unruffled, allows a strengthening and a kind of re‑equilibration, a sort of a reset energetically, and this will assist future incarnations because life is a continuum, they will come back to a starting point that will be a level playing field having had a "time-out" life, a vacation interval, and that will enable them to have a greater likelihood of advancing and bringing in healing for the negative karma of their past. The "time-out" life will be experienced as such because they will not be engaging in negative conduct that worsens things immediately and adds to their troubles and any kind of turmoil that would inevitably trigger old karma quite forcefully. So it will be a life of equanimity and likely a life where they are open and able to make contributions through loving kindness to themselves as well as others. That will create positive karma for them perhaps in the first time after many other lifetimes. That positive karma will carry forward and that is what also contributes in the subsequent incarnation to get them started on the right foot, so to speak, and increase their likelihood of having an upward and successful trajectory they can build on and perhaps begin finally to turn things around and move in a positive direction through a series of lifetimes, gaining ground each time with each new overall success, and hasten their return to divine alignment. So this is something well-recognized and supported by the divine to be a healing answer for people in dire straits and will be not only allowed, but supported and recommended by Creator when this is appropriate to give a person a chance to recover from being in a downward spiral.