When the Starting Script is inserted into the output GCode, [toolchange_retract_distance] and [toolchange_retract_speed] are not replaced.
In order to use a Tool Change Script, it is necessary to setup the initial conditions so that the first insertion of the script at the beginning of the GCode output will actually retract the old nozzle and prime the active nozzle. At this point in time, the old nozzle is undefined (i.e. {IF OLDTOOL=0} and {IF OLDTOOL=1} are both not true) so the only script available to setup the initial conditions is the Starting Script.
If having [toolchange_retract_distance] and [toolchange_retract_speed] usable in the Starting Script is undesirable, this problem can also be solved by providing an {IF OLDTOOL=something} in the Tool Change Script so that it can handle the first use case. This may actually be the better solution.
