I think there are two motivations that get blurred pretty quickly:

a) you find a particular context that executes well and want to preserve parts of it or not have to repeat explanations

b) you want to continue a session so you don't have to rebuild the context from scratch

I think A is something where it's totally reasonable to preserve pieces as part of like a prompt library or equivalent, or directory-specific agent files, that kind of thing.

I think B is much more likely to lead to problems if you do it over a long time, but it can be pretty useful for getting the last drop of juice out of the metaphorical orange.

I think the antipattern (that I've done myself, admittedly) is swapping between different restored contexts for different tasks or roles - at that point you should be either converting it to more durable documentation if warranted, or curating it more specifically than "restore the entire context" even if it's just one-off.