There is no volume dependent slowdown. You might have a slowdown based on z position depending on this setting:
/** If you print on a moving bed, it can become more shaky the higher and bigger
your print gets. Therefore it might be helpfull to reduce acceleration with
increasing print height. You can define here how acceleration should change.
You set ACCELERATION_FACTOR_TOP to the factor in percent for the top position
of your printer. Acceleration will then be modified linear over height.
INTERPOLATE_ACCELERATION_WITH_Z sets, which accelerations get changed:
0 = do not interpolate at all
1 = interpolate x and y acceleration
2 = interpolate z acceleration
3 = interpolate x,y and z acceleration
*/
#define INTERPOLATE_ACCELERATION_WITH_Z 0
#define ACCELERATION_FACTOR_TOP 100
Only other limit is extrusion speed when you need to move faster then max. e speed.
