[Azu]

i can confirm zoning does increase Mage DS duration, at least with 2 of them. I tested this with Shield of Lava (level 49 DS) then with Barrier of Combustion (level 39 DS)

Shield of Lava Zoning at:
0:18 (fading) Increased the Timer to 1:18
0:30 Increased the Timer to 1:30
1:00 Increased the Timer to 2:00
2:00 Increased the Timer to 3:00
3:00 Increased the Timer to 4:00
4:00 Increased the Timer to 5:00
4:54 (Fresh cast) Increased the Timer to 5:54

Barrier of Combustion only increases the time by 1 Tick regardless of when you zone.

so it would appear that zoning with a Shield o Lava increases its Duration by 1 min, and can extend the timer past its max duration from a fresh cast. zoning a 2nd time will not increase the timer again. only the first time zoning with the DS. IE zoning at 4 mins will increase it to 5 mins, but zoning again right away will not increase it a 2nd or 3rd time.

While it isn't a very important bug or much of a big deal. it is there.

I'll test the other mage DS's later. (i need to go buy them lolz)