Jhana as a Gateway to Concentration, Insight and TMI Stage Progression

Recently, I've really taken to a meditative practice called "Jhana". In a nutshell, a Jhana is an altered state of consciousness that results when the meditator enters into a state of "flow" or "absorption" during the course of a meditation. For a detailed description of the different Jhanas and instructions on how to access them, check out meditation teacher Leigh Brasington's article on the topic over at Lion's Roar.
I believe that Jhana practice is a great way to mix it up when you become a more proficient meditator. It's also a way to sharpen concentration even more and to get a taste, even if transient, of the indistractable attention that is to come as the meditator approaches exclusive and effortless attention on the object of meditation (i.e. "single pointed attention", which is equivalent to Stage 8 according to the model). Additionally, once one emerges from Jhana, the post-Jhanic mental state is very conducive to fruitful insight practice
I'd like to encourage meditators who feel that they can get into "access concentration" to incorporate Jhana practice into their daily practice and not wait for a retreat to do so. Once you get 1st Jhana, 2nd and 3rd aren't that difficult. Even 4th is within reach. Fifth Jhana, on the other hand, seems to require more practice and would thus be better suited for playing around with on retreat (I have yet to reach 5th Jhana, so I'm going by anecdotal evidence and not first hand experience). For a description of the first four Jhanas, check out the following article.
In terms of structuring sits, I've found that splitting a sit into three thirds has been very supportive of my practice and allowed me to deepen concentration and insight practice. What I do is I spend the first third doing standard mindfulness of breath, the second third doing Jhana practice, and the third third doing insight practice (e.g. see/hear/feel, meditating on arising and passing away, Do nothing, Choiceless attention, etc). You can use interval bells to help you transition from one practice to the next.
By adding flavor to your sit in terms of different practices in the way that I suggest (or other ways, of course), you may be able to overcome the boredom that sometimes arises when a meditator first achieves exclusive attention on the breath (equivalent to TMI Stage 7). Another reason to structure sits this way is that as the meditator emerges from Jhana, the mind is incredibly concentrated, which is ideally conducive to insight practices.
Much Metta to you and may your practice continue to blossom and mature!