I'll test this later today! I've used pipx before to make binaries available (which would help the manim-binary in our case too), but I've never tried to interact with the environments created by pipx (e.g., in order to add more packages, or to use it with an IDE).

Installing additional packages to the same pipx-managed venv as manim is then located in is possible via pipx inject manim package_name, and IDEs could probably be made happy too if we documented that the manim-venv is located at ~/.local/pipx/....

If everything works smoothly like that, I'm fine with recommending pipx. Otherwise, if the interaction with the pipx-managed environment is awkward, I'd probably rather recommend creating a plain venv instead.