I do not really see much difference in overall damage when overdriving either, But I just choose to overdrive the Bloodsong since its damage has a bigger AoE than the Twisted Stroke. Whether you want to overdrive Bloodsong or Twisted Stroke is really just personal preference imo.

I recommend overdriving the Afterburn simply because the cool down reduction is really valuable, it allows you to use it more often to disrupt enemy positioning, especially since glaive can be kited if he don't have this as a gap closer. The lower cooldown can help you peel for your (hopefully ranged) laner/carry better too, frequently knocking back enemies away from your laner/carry so they can keep their distance to deal damage.

Thanks! so if enemies are out of the bulwark, they can be knocked back into the bulwark. Sounds good with Crystal Lyra.