STIV: Bird of Prey looks like it's going to warp within the Earth's atmosphere. STTMP: They went to warp within the solar system.
Those are just two examples. I'm sure there are plenty more (I think they did that regularly throughout TNG).
The only mention of that requirement that I remember is a captain's log from TMP, where Kirk says they have to risk going into warp while still in the solar system. We don't know why it was considered a "risk"...perhaps it's a space traffic issue to prevent ships from warping in and out and causing collisions by providing a "non-warp zone" for in-system traffic. Not every restriction has to be based on catastrophic limits of technology (and, based on on-screen evidence, there doesn't seem to be a technological reason behind that restriction).
Again, though, this is an irrelevant issue. The story doesn't hinge on whether the ship enters warp within a solar system.
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