Hey Elliot Xia, you are definitely right: The way I described in the article only works for same OS (I used ubuntu-to-ubuntu as an example). It is possible to make yml file that is cross-system compatible (from what I just learned from a conda-forge core dev today), but the creation of the yml file seems to be more manual and may need to exclude specific version number. Below is an example:

name: sandbox
channels:
  - conda-forge
  - defaults
dependencies:
  - flask
  - flask-cache
  - flask-cors
  - pip:
    - jupyterlab

if you have anything that is very version specific, I currently do not know how to make it cross-platform compatible with conda :(