Slic3r has been modified to propagate the following filament specific

values to GCode generator, one per active extruder:

bed_temperature
bridge_fan_speed
cooling
disable_fan_first_layers
fan_always_on
fan_below_layer_time
first_layer_bed_temperature
max_fan_speed
min_fan_speed
min_print_speed
slowdown_below_layer_time

Now it remains to extend Slic3r to correctly apply these values.

t/multi.t

@@ -128,7 +128,7 @@ use Slic3r::Test;
     $config->set('fill_density', 0);
     $config->set('solid_infill_speed', 99);
     $config->set('top_solid_infill_speed', 99);
-    $config->set('cooling', 0);                 # for preventing speeds from being altered
+    $config->set('cooling', [ 0 ]);             # for preventing speeds from being altered
     $config->set('first_layer_speed', '100%');  # for preventing speeds from being altered
     
     my $test = sub {