Please assign a GLEP number and copy the draft contents [1]. Relevant RFC at [2]. [1]:https://wiki.gentoo.org/wiki/User:MGorny/GLEP:INSTALL_MASK [2]:https://archives.gentoo.org/gentoo-dev/message/af5de8be051fdf60d4d4aef97df6e683
Have GLEP number 69. Moved.
I haven't made the necessary progress for over a year, and I don't expect to have time to work on it in the near future, so I've marked it Deferred. We can return to it when I (or somebody else) has the time to implement it in Portage.