Similar to issues encountered on other heroes, Duration / Range extension does not appear to apply to Warden's Ult.
Tested in Sandbox and verified (did work with Alchemist Flask).
Had Divine Barrier, Superior duration, superior reach, and divine kevlar, and it appeared to be 23M radius and 8.4 sec duration, both were static when dash-jumping with arcane surge.
Tested in Sandbox and verified (did work with Alchemist Flask).
Had Divine Barrier, Superior duration, superior reach, and divine kevlar, and it appeared to be 23M radius and 8.4 sec duration, both were static when dash-jumping with arcane surge.