Sqz,
(I was hesitating for a moment in view of some of the latter posts. As long as thoughts are shared decently and respectfully there is reason to post.)
If we set aside all that is being debated inconclusively for centuries, a general agreement seems to be that Patanjali took upon himself a huge task of common codification of the theory and practice of Raja Yoga, both of which pre-existed with unpteen variations.It is also evident that he used such highly optimized expression that each syllable exists in the sutras only with precision and justification.
That makes “now” far less casual and we need to speculate in favor of some significant meaning. “Now” of course means “after something”. Possible options are (1) after some basic preparatory training (since he uses but doesn’t explain terms like guna, purusha etc) or (2) after being eligible in the strict guru-shishya mode for the rigors of Raja Yoga.
My guru, who gave us a different sequence of sutras, that like a key opens up a grand new dimension of sutras (it is in my book) used to say that a guru used to pass on this sequence to the eligible disciple and would say, “now, here are the detailed instructions,”
But, yes many things about sutras are intriguing, yet fascinating and teaching.