During SP, it probably takes me around 20-25 seconds to inhale comfortably, while that even if I try to prolong the exhale with the ujjay, it takes me about a fourth or fifth the time of the inhale. Is that alright? Or should I try to even them up somehow?
Same as what I said in the meditation topic. Do the process as described in the lesson. The inhale/exhale time will change as you keep going. So for now, just focus on tracing the spine.
I would try to open up the inhale in this case. Rather than struggling to lengthen the exhalation instead, open the throat more and inhale without restriction. Once the inhalation is shortened to about the same length as the exhalation then you can slowly work on lengthening the exhalation. Yogani teaches and I agree that there should not be a restriction on the inhalation during pranayama. Inhalation should feel spontaneous after the breath has deeply and thoroughly been exhaled. The inhalation is a natural regulatory function and should be spontaneous, natural, not restricted. Maybe slight control just to smooth it out very gently but I would make no effort to prolong the inhalation. As for exhalation not only is it good to gently restrict the throat in ujjayi bit also I have found that special attention should be made to the end of exhalation to be sure that the breath is deeply and fully squeezed out before beginning inhalation.