Hello! Thanks for the heads up. I will make sure to create a feature request for this. As a workaround you can always install any extension by downloading the VSIX and then installing it from the Codemix’s Extension Manager:
1. click on Help > CodeMix Extensions.
2. click on “Install from VSIX file” link.
3. choose a previously downloaded vsix file.
Cheers!
Aaron Lara