Asolutely. It doesn't have to be an either-or. I use gptel and org mode when I was to be really hands on driving the development. It's a very different mode of interacting with models, and the way newer models are trained to play nice with harnesses makes them very obedient.
A generalized llm prompting library for clojure, and seeing what falls out from that. I wanted something which was fun to use in an interactive way, but not too abstracted.
I don't let it execute emacs lisp itself, but elisp generated in org mode babel blocks which is instantly executable is a fine way to have gptel improve itself.
The more you can afford to build up your understanding of the problem space and define what inputs & outputs look like, the more flexible you can be with evals. Unfortunately, this is a lot of work and requires thinking and discussion with your team and those involved.
I agree, and this is why I tend to use gptel in emacs for planning - the document is the conversation context, and can be edited and annotated as you like.