Would creating a `main.py` with the dependencies installed either as a uv project or inline work for you?
One thing I did recently was create a one-off script with functions to exercise a piece of equipment connected to the PC via USB, and pass that to my coworkers. I created a `main.py` and uv add'ed the library. Then when I wanted to use the script in the REPL, I just did `uv run python -i main.py`.
This let me just call functions I defined in there, like `set_led_on_equipment(led='green', on=True)` directly in the REPL, rather than having to modify the script body and re-run it every time.
Edit: another idea that I just had is to use just[0] and modify your justfile accordingly, e.g. `just pything` and in your justfile, `pything` target is actually `uv run --with x,y,z ipython`
Edit edit: I guess the above doesn't even require just, it could be a command alias or something, I probably am overengineering that lol.