Looking for some help calibrating a hold-to-melee macro setting, any help greatly appreciated

Wonder if someone can help me out. Trying to set up a hold-to-melee macro in G Hub, in order to minimize any repetitive stain on my hand. Having trouble nailing down the millisecond value to use between inputs, since the attack chain right now seems to always carry on for too long after I take my thumb off the mouse button. Anyone have a value they use that they're happy with, or are the extra attacks after releasing the button just something to get used to? Thanks for taking the time to read this.