I'd also like to give mamba a vote. I failed to install qiime2 with conda in ubuntu-server 22 environment on my old surface pro4 (which can not work without being plugged ). It took a very long time for the installation process and I finally gave up. In contrast, mamba worked quite fast and completed the installation just in one try. My very recent installation is version 2023.2.
Mamba is so much faster, so if it's ready to use in production that would be awesome! Would you be willing to help us out with testing?
Sure! It would probably be best to include a mamba install in the qiime2 CI testing. It appears that neither a conda nor a mamba install of qiime2 is currently tested in your github actions. Do you want me to send a PR with an updated ci.yml?