Invincibility Duration stacking?

An overall can have two particular types of Invincibility Duration bonuses that I'm particularly interested in: one that increases your invincibility by +1 second, and another by +2 seconds.

What I want to know is if I get +2 and +1 on the same overall, will it stack to an additional +3 seconds resulting in 4 seconds of total invincibility, or will only one of them work?

I've heard two different things from two different sources, so I'm not sure which is accurate.

Thanks in advance.

They don't stack. I believe like boss damage, total damage, and other things that don't stack , it'd take the form of the lower tier over the higher. (1 second invisibility)

They don't stack. Like boss and total damage, the lowest line takes effect. Set bonuses do stack though when they come in the future.

Is that confirmed though for set bonuses? I've heard from DBs that 30% boss on the dagger and 30% boss on the katara don't stack despite being on different items so it's not like an item specific value or line priority. Somehow I doubt set bonuses will allow stacking if the two separate items don't allow for it.

Set Items just get the .img of the potential stat. I doubt they stack.

Is that confirmed though for set bonuses? I've heard from DBs that 30% boss on the dagger and 30% boss on the katara don't stack despite being on different items so it's not like an item specific value or line priority. Somehow I doubt set bonuses will allow stacking if the two separate items don't allow for it.

The 30% on dagger works for dagger hits in a skill and the 30% on katara does the same to it's hits, so they work together but just for their respective weapon.