I do light coding and writing and I used to think what you're thinking now. But in practice, I've found that I don't really need two sets of everything. Do you have any actual uses cases? There may be a particular fix for specific issues.
- If, as I do, you write consistently in Markdown (or some other markup) you can use those settings to tweak the environment.
- Consider OS-specific settings. For example, I am more likely to code than write on Windows and vice-versa on Linux.
I think @facelessuser had a plugin that switched out some parts of User on-demand, but I don't think he ever released it. You may want to bug him about it