I've had luck with telling it to just rewrite a certain part of the code. You can copy and paste the relevant part and ask it to just rewrite that or you can direct it using natural language, you just have to be specific. If the chat is getting too long you can also copy just the important parts or the code so far into a new chat and start from there.
I've found that copying the result of one session to the next can work pretty well (like when you hit token* limits), especially if you have the bot include comments.
It would be awesome if gpt4 could be made to edit the code and therefore, it didn’t have to regenerate it from scratch every time.
The regeneration also chews up a lot of the token limit, so it forgets crucial parts earlier on in the conversation.