The Air Wake feature. If I’m not mistaken, it’s supposed to make heavy armour lighter.
This is due to a special effect that the shield has. Gravity Field comes to mind. This special effect that uses a gravitational field has a high probability of developing in shields in the Spirit Turtle Series, and it seems to have the power to somehow cause floating objects to fall.
If that was enhanced by the shield’s effect, then even Firo would say it’s hard to jump around.
I nod at the fact that if the Spirit Turtle materials have even just a tiny bit of this effect, then their affinity with the Air Wake feature would be bad.