Background: I don't visualize the energy moving up the spine, I instead move my attention/focus/concentration up and down the spine and "guide" the energy along the channel, letting it go at its own pace/speed/size/width without forcing it in any kind of way.
Issue: I can't do very long breaths like most of you guys. During spinal breathing, if I run out of breath (on the way up for example) but, the energy/focus/concentration is only halfway up the spine, can I instantly switch to visualizing a thread and very quickly trace it the rest of way up to the brow to finish the path?
Concern: I know we shouldn't just stop halfway even if we run out of breath, but I also don't want to simply "jump" to the brow either bypassing all the path in between.
It is okay to jump to the third eye on the top of the inhale, and to the root on the bottom of the exhale. You are in a sense etching the path by the overall practice of tracing the spine. Canyons are etched into the earth in a similar manner, by repetition and time. You are doing great.