[gentoo-dev] Need clear semantics for packages with binary entities

I’m suffering from the fact that users can distinguish packages containing
binaries just by eye. There is no mechanism to allow/ignore such packages.
For license restrictions we have ‘package.license/’ whitelist.

I figure out the following binary entities in portage’s packages
that (to my point of view) need to be clearly defined as BINARY:
1. *-bin packages (maven-bin, icedtea-bin)
2. firmware packages (linux-firmware)
3. purely binary packages that are installed without any notion
they are binary or source packages just like Ubuntu’s ones
(app-office/upwork)
4. packages with pre-compiled bytecode/objectcode that are installed
like packages in #3.
(geogebra, many packages with .jar files in dev-java/*)
5. packages with ‘-binary’ USE-flag. Semantics of ‘-binary’ differs:
(seabios) binary     : Use official upstream pre-built binaries
(ghc) binary        : Install the binary version directly, rather than
using it to build the source version.
(scala) binary : Install from (Gentoo-compiled) binary instead of
building from sources. Set this when you run out of memory during build.
(etc...)
6. packages that need binaries to compile/bootstrap (sbcl)
7. to be continued... I guess

#1 semantics has no control. Such packages may be installed as a
dependency
without warnings they are binaries.
#5 semantics are not clear (defined in manifest.xml)

The only binary entities under users’ control are:
1. packages from “PKGDIR” installed with ‘emerge --usepkg’
2. packages with -binary USE-flag

I wonder if Gentoo’s devs can do something with the problem.
I think it’s problem in source-based Linux distribution.