no, there is no way around the standing IME. it is taught for good reason. every xingyi form starts off with holding the santishi/pi chuan posture for at least a short time for a reason. the skills cultivated during this practice directly translate to how well you will be able to maintain and utilize root,structure, and internal and external coordinations while moving. one of the main goals is to develope a certain type of body structure that can be used with any other movement.
also, it is good to note that all other postures in xingyi may be held as well. but a definite focus is given to this base posture.
i definitely agree with snake77 - dont pass on it or take it lightly if training xingyi.
Tang Shou Tao founder Hong Yixiang and his teacher Zhang Junfeng taught Xingyiquan first out of the three neijia because they believed it taught the basics of IMA best, and takes less time to cultivate qi in and helps improve the bagua and taiji skills later.
sounds true enough. i believe hong actually made that the basis of his teachings, not sure if zhang did though. i would have to ask my teach on that, since he learned from hong.
but, anyways, yes, xingyi is definitely the easiest to gain a basic understanding of how power is used and focused in the so-called IMAs.
i do wonder though, sometimes, if people stop learning xingyi after 5 or so years because they think it is basic? because, though the movements appear simple enough, there can be a helluva lot going on if you have trained every aspect of the movement in detail.
so, i would say, sure, you can gain the basic ideas and concepts of power through xingyi perhaps quicker than taiji or bagua, but, there is also a lot more to xingyi. and anyone who does take the time to go over even the basics again and again will end up finding things that they can still train even after years of work.