Why Maturin places build artifacts of mixed Rust/Python project into the source tree instead of installing them properly?

[yesint]

I'm puzzled by the way how Maturin handles mixed Rust/Python projects. As described here "When using develop, maturin will copy the native library and for cffi also the glue code to your python folder. You should add those files to your gitignore". I can't get why this differs so much from the behavior for pure Rust projects.
When you have rust-only extension maturin develop will install it automatically to the active venv or to your .local/whatever if you not under venv. In contrast, for the mixed project extension is placed to your source tree polluting it. Then you need to move it manually to the place where your Python can see it. This is very inconvenient and I can't understand why anybody will actually need it as a default behavior.
What is the reason of this inconsistency? Is it possible to override it somehow and install the mixed extension properly?