Before coming to AYP I was practicing a number of spinal breathing variations. I was always seated crosslegged (Burmese style) without the back leaning on anything. Even though I know it's important to seamlessly go from pranayama to Deep Meditation, and I know having the back propped up is important for DM - having my back contacted with something feels disorienting.
Harder to feel and/or visualize the prana moving through the Shushumna. Is this something to be worked through too or is it better to continue unpropped and transition at some point?
You don't need to use back support of you don't want to, for either Spinal Breathing or Deep Meditation, or any other AYP practice. Back support is recommended as an option for those who find it difficult to sit without it, but it is not a requirement.