"Lenghtens xxx duration on foes by yyy%"

Ok, many weapons have this prop, but what exactly does it mean?

-The effect is applied only when you use a physical attack to inflict it? or works even on spells/skills that inflict xxx ?

-Only if the condition if inflicted by you? what about a teammate attacking the same target?

-What happens if you switch weapons? the "lenghten duration" check is done only upon infliction (so you can swap and still have the lenghtned effect ), or you must wield the weapon for all the duration of the condition?

thx to all

I believe...
1. Not sure, but IIRC it affects physical attacks and skills/spells.
Edit: Just tested on a dummy with Enfeeble+Lengthen Weakness, the mod affects the spell.
2. Only by you.
3. On infliction. You can swap and get the lengthened effect.

Note that a previously lengthened effect can get lengthened again. So if you use Chiblains to inflict poison on yourself it's now been lengthened in duration once. Then you use Plague Touch to send it on to someone else and it has just gotten its duration lengthened yet again.

It's fun to wonder how many times you could potentially bounce a condition around your team lengthening the duration (everyone would have to have the condition lengthening weapon) before sending it off to an opponent... though it's really not practical to use in battle, just something fun to think about.