caerus - check out the embryonic breathing book or dvd. these descriptions are fancy speak for "immersing yourself in your breath" or to "be the breath" in a manner of speaking. again just imparting superficial words onto experience, which is in truth beyond words; to see, to bleed - cannot be taught. so really what you're shooting for is to "regulate the breathing" until you can "regulate without regulating," or - simple focused exercise (in this case breathing) builds muscle memory. so build the muscle memory of proper breath (and proper sitting, proper standing...) and then you can reach a point where that "percentage of awareness" you have to spend is much less consumed by breath (and posture) - what that does is leave you with more awareness with which to focus on....your awareness
to access deeper levels, let the foreground fade away until the background becomes the foreground - there's the point where you begin to experience subtleties. (how can you access the background without it being ostensible noise unless you first calm the foreground?
)
anyway, this is related to "uniting the shen" with the breath, for really, once you've calmed the breath to the point where there's...simply...respiration, that is a gongfu that naturally leads towards uniting the shen with the breath. which, once you've established the practice and are regulating the breath without regulating, it is easy as...heh, turning one's hands over....just sitting down, calming, and uniting shen & breath
so by that rationale, holly - doing it twice a day will certainly have more benefit from the muscle memory aspect, but - certain exercises require certain repetitions in order to have a discernible or maximal effect. I'm honestly not qualified to accurately quantify the difference of the benefits of the two scenarios, but - how much extra time will it take for the extra few reps to just make it doing the full form twice a day?
I'll leave ya with this: you manifest what you train for. which reminds me of a quite yat chum put up a while back:
Keep your thoughts positive because your thoughts become your words. Keep your words positive because your words become your behaviours. Keep your behaviours positive because your behaviours become your habits. Keep your habits positive because your habits become your values. Keep your values positive because your values become your destiny.
-Ghandi
"Stay on target!"
-Red Leader