For the weapon I went for both Battle-readied Damage Buff and Battle-hardened Incoming Damage but... I don't think these legacies actually work. At least when you are in the Battle-ready state the tooltips go up only by 5% and not by >18% as they should in my case. As for maintaining this buff, it does appear after Battle Shout, Shadow Lament and Time of Need. The skills which are consuming this buff (Pressing Attack and Dev Blow) should deal an increased damage since this buff is always active for them. Not working now.
Another broken legacy is Grave Wound Damage - it does not increase the bleed damage at all.
Overall I am glad that the new area rewards include some Imbue Legacy Replacement scrolls. I may use it for my sword if these legacies are not fixed in the nearest patches.
Light-type Damage is a must for a dps emblem in my opinoin, was so even before U16. Shadow Lament deals light damage so the legacy buffs it too. On an imbued weapon Light Damage goes up to 35% while the SL damage only up to 21%. I also prefer to keep Time of Need Duration and Sure Strike damage on my dps emblem instead of some healing legacies.