[Autumn]

Seems that ambidexterity will let you use your sub-equip to Wazabane, even if your sub-equip isn't a katana.

EX:
Person goes to Wazabane with their mainhand katana, instead Wazabane's the target with off-hand spear.

[Egil]

The same for Parting Shot. If you have a multiround gun and use Parting Shot with ambi, your sub will attack the target with as many rounds as the main weapon.

It's not useful but it's pretty funny to strike with a knife four times instead of two.

[Neus]

Should be corrected in 1.57b.