This is important: the point of modeling a pattern is not to copy; it's to learn.
- Sometimes you need to copy a pattern rigidly in order to understand how it works.
- Sometimes all you need is inspiration, and the pattern is something you can adapt.
What's the right approach in a given situation?
It depends on the lesson. For example, Writelike grammar lessons are rigid, but genre remix lessons are very loose.
Ultimately it's up to you: patterns can only take you so far, and you always need to be prepared to think for yourself.