And looking at the manual, there appears to be cvar settings that you may alter when making your own server to have the melee speed time you want
am_prepunch_delay : 0.200
am_prepunch_delaystruggle : 0.100
am_prepunch_driftspeed : 280
am_prepunch_max : 12
am_prepunch_maxstun : 6
am_prepunch_mincombo : 3
am_prepunch_stunperpunch : 0.750
am_strongrange : 1.350
am_struggle_arrowtime : 0.500
am_struggle_enddelay : 1.500
am_struggle_maxarrows : 6
am_struggle_maxextanges : 2
am_struggle_startdelay : 0.750