If you look at videos of Grandmaster Wei Shuren performing the same technique in the 22-form and the 108-form you would notice that there are slight differences.

An example is the transition at the beginning of Brush Knee, Twist Step. The 108-form video of GM Wei shows him doing this transition differently from his video of the 22-form.

The 22-form transition is easier for a beginner to learn, however, from an application point of view the transition from the 108-form makes more sense.

Ignoring the point about application, you can perform the 22-form differently and still be correct as long as you follow the principles.

But if you are interested to use the 22-form for push hands then the question would be what is the application for the 22-form transition in this case. Is it an effective application? Does it make sense?

For training I follow the approach of the form should follow the application. If not, then while your form performance can look good and adhere to the principles, when you try to apply the technique in push hands you would discover that you could not use it without having to modify the movements.

Even if you practice to follow the applications right off, it does not mean that you can use the techniques straight away. You still need to go through a period practice, testing and refining before you can use the technique properly.