Isn’t the exact reproducibility of the environment overrated?
I mean, having it is a nice feature. But don’t we actually expect that updating all non breaking versions still keeps everything working?
Maybe there should be another level of “instantiation”, that adds the latest available non breaking versions of the packages compatible with the project, and just warns the user if updates are available. And if the user updates, other environments sharing the same non breaking versions of packages should benefit automatically from that update, upon this level of “instantiation”.