Keyboard layouts: console-setup limitations

[Yotam Medini]

Hello {console-setup / input-configuration / XKB / Hal} guys

This package-set following 'Hello' may reflect on the some confusion.

Recently I am configuring my Linux box's
    /etc/default/console-setup
with the following values:
    XKBLAYOUT="us,il"
    XKBVARIANT=",lyx"
    XKBOPTIONS="grp:alt_shift_toggle,grp_led:scroll"
This works fine for me.

So far, I failed to see accurate documentation saying
How rich can these values be. In once case I tried
to add a third (Arabic) layout, by putting
    XKBLAYOUT="us,il,ara"
But then upone running:  
    dpkg-reconfigure console-setup
I get the error:
    The configuration file /etc/default/console-setup specifies a keyboard
    layout and variant that are not supported by the configuration
    program.  Because of that, no questions about the keyboard layout will
    be asked and your current configuration will be preserved.
that comes from 
    /var/lib/dpkg/info/console-setup.templates
This is probably reulted by the code in
    /var/lib/dpkg/info/console-setup.config
that has:
    case "$XKBLAYOUT" in
	lt,lt) ...
	jp,jp|us,jp) ....
	cs,cs|us,am|us,ara|us,ben|us,bd|us,bg|us,bt|us,by|us,deva|us,ge|
        us,gh|us,gr|us,guj|us,guru|us,il|us,in|us,ir|us,iku|us,kan|us,kh|
	us,la|us,lao|us,lk|us,lt|us,mk|us,mm|us,mn|us,mv|us,mal|us,ori|
	us,pk|us,ru|us,scc|us,sy|us,syr|us,tel|us,th|us,tj|us,tam|us,ua|
	us,uz) ....
	*,*)
	    unsupported_layout=yes

Regarding Debian & Ubuntu installation.
In my opinion, the selection of a language for the installation process,
should be independent of the choices of the languages to be supported
in the final system.
Consider an English speaking person, who installs a system
for persons that use French and Spanish.
He would want to select English just for the installation,
and select two other languages for the configured system.

Any further thoughts?
regards -- yotam