forms and techniques are 2 distinct tools we have within the system(s) mr. parker left us. the forms are designed for solo practice, and techniques are meant to be practiced with an opponent. while there is much to be learned from doing a form with a partner throwing the attacks, and learning the movements of a technique alone in front of a mirror, this is not the main purpose of these tools. the forms will train you to internalize correct posture, stances, balance, fluidity, rooting, and agility. techniques will test all of the above, with emphasis on reaction, timing, distance, control, and targeting.
maybe, just maybe, the earlier forms are more similar to the chinese arts, where a student learns a form initially to learn how to move without understanding the full nature of the application. then, as applications reveal themselves through the students development, it is realized that there are several applications contained in each sequence of the form when examined with different intents.
perhaps, the some of the techniques we practice are just derived from those abstracts...and others are yet to be derived...
the later forms are more obvious in moving from one technique to the next, some with mirrored versions. but don't these forms still provide us with the same purpose and benefits as the earlier forms? are they there for us to internalize posture, stances, etc through solo practice? could this be a metaphor for the development of the art from being shrouded in asian secrecy to something more 20th century american?
through my eyes, as i see it today, practicing a mirrored technique is very different to practicing a form containing the movements of mirrored techniques. i am right handed. lucky, i guess, unless i have dreams of being a major league first-baseman. i think there is something genetic that made me this way, and 43 years later it ain't changing. i can work my forms to develop balance, agility, etc, but it's not going to make me left handed.
so, given KT's example of Heavenly Ascent, why, under duress would i choose to react to a 2 hand choke "symetrical attack" using my less dominant side? why do 5 Swords from the left when you can do Sword of Destruction or Unfurling Crane with the confidence of using the dominant side? maybe its just me, and others more ambidextrous would...
notice i said, "as i see it today"... i may reach a higher level and come to a different realization with more practice and time in the art...but for now, i use my forms to try and internalize the principles, and techniques to actualize them.
now, i've got some exceptions where the mirror techniques could come in handy. say you're grabbed around the waist from the rear, and your thinking Spiraling Wrist/Twig (depending on your nomenclature), and you look down and see fingers pointing to the left. i'd think you'd want to go with it as the mirrored version. same true for getting stuck with your left arm hammerlocked...it would help if you'd have trained those techniques.
so, do we pick and choose to see which ones are practical and which aren't needed to be mirrored? or do them all for completeness? well, i doubt it makes anything complete since symmetry can go beyond left/right mirroring (good reference to prone position tech training KT!)
sorry i don't have any direct answers here, just some thoughts based on where i am in my training today.
pete