I tend to avoid editing previous messages because it breaks my mental model of the sequence that got me to the current state. That's more of a bias from my goal to do "research" into how these models work though - I'm always trying to maintain the cleanest possible record of what I did so I can learn from the transcript later.
Also ChatGPT has a pretty big context window. Gemini supposedly has the biggest useful context window (~millions of tokens), though I don't have personal experience.