SCREEN_07="xfreerdp <params>" lts.conf directive, or the
SCREEN_07="rdesktop <params>" directive,
so as long as it doesn't enforce any parameters, why are two separate
scripts needed?
The only hardcoded option in that script is
RDP_OPTIONS=${RDP_OPTIONS:-"-f -u ''"}
...which is only there for compatibility with older LTSP versions, and
can surely be replaced or completely omitted in lts.conf.

