This sounds like an terrible idea! "Prereq" is short for "prerequisite". It is meant to indicate what version is required for your module to function. It is not meant to indicate which version is the hippest, newest bleeding edge in the repo!
You should specify the oldest possible version of the modules you depend upon. You are supposed to specify the minimal version number, the one that if you can't find one at least that new, then your module can't be installed because it doesn't work with that really old version of the module. A prereq version number does not prevent the installation of a newer version of the module.
Please stop doing this.