netclasses in eeschema

Steps to reproduce

1. have some netclasses ready and a schematic
2. rigth click a wire. Sometimes you have "net must be labelled to....." sometimes the class list.
3. go to File->SchematicSetup, assign the class you want to the net you want. No label thing
4. close and reopen your project. From eechema, assign a net class to a wire. No dirty flag. You can quit whiteout saving but the change is silently saved in project.
5. Being human, I entered "1 mm" for testing eeschema classes. Now transformed to 0.991, not voluntarily
6. why "Tools->Bus Definitions" and "File->SchematicSetup->Netclasses...... ?
7. Change width of a netclasse, in eechema, effective immediately. pcbnew, euh did I forget validating my change ?

KiCad Version up to commit 558f4b4b

Version: 5.99.0-unknown, debug build

Libraries:
	wxWidgets 3.1.4
	libcurl/7.66.0 OpenSSL/1.1.1d-fips zlib/1.2.11 libidn2/2.2.0 libpsl/0.20.1 (+libidn2/2.2.0) libssh/0.8.7/openssl/zlib nghttp2/1.40.0

Platform: Linux 5.3.18-lp152.44-default x86_64, 64 bit, Little endian, wxGTK, KDE, x11

Build Info:
	Date: Oct  8 2020 22:00:05
	wxWidgets: 3.1.4 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.66.0
	OCE: 6.9.1
	Curl: 7.66.0
	Compiler: GCC 7.5.0 with C++ ABI 1011

Build settings:
	KICAD_SCRIPTING=ON
	KICAD_SCRIPTING_MODULES=ON
	KICAD_SCRIPTING_PYTHON3=ON
	KICAD_SCRIPTING_WXPYTHON=ON
	KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
	KICAD_SCRIPTING_ACTION_MENU=ON
	BUILD_GITHUB_PLUGIN=ON
	KICAD_USE_OCE=ON
	KICAD_SPICE=OFF
	KICAD_STDLIB_DEBUG=OFF
	KICAD_STDLIB_LIGHT_DEBUG=OFF
	KICAD_SANITIZE=OFF