I do this as well and it works quite well for me like that!
Additionally, when working on microservices and on issues that don’t seem too straightforward, I use o3 and copy the whole code of the repo into the prompt and refine a plan there and then paste it as a prompt into cursor. Handy if you don’t have MAX mode, but a company-sponsored ChatGPT.
I do this too by pasting only the relevant context files into O3 or Claude 4. We have an internal tool that just lets us select folders/files and spit out one giant markdown.