It can be a good idea to plan your practice sessions. The benefits are obvious: it’s a way of ensuring that you cover all the bases (some flexibility practice, some stance development, etc) and perhaps devote special attention to particular techniques. But are there drawbacks?
A schedule doesn’t allow for much creativity. It slides quite easily into going through the motions, in the worst sense. Whenever I persist in a training schedule (regularly over an extended period) , I feel improvement in certain areas, but end up rebelling against it. Master Chan tells us, “training must not become drudgery.”
So, how often do you revisit and refresh the training regime? How much time do you allow for more spontaneous and creative practice, without the fundamentals suffering? I have never met the person able to provide a definite answer, and perhaps there isn’t one. But I think that when the practice routine seems off-putting rather than motivating, it’s better to do something else.