[Autumn]

The 10 star greatsword Gigantys does not seem to deal it's bonus weight damage in the sub equipment slot

It does not work properly with some arbalest skills either (damage wise, I suspect from the bonus weight mostly from the UL and weapon parts.)

also it does not seem to get range buffs from Huge blade and Giant Gene.

[Neus]

These have all been corrected. The Arbalest one was a bug that was applying to all sub-weapons, since it was just checking the base weight and not any modifying factors.