I don’t know if this is working as intended, but…
Use Inspiring Reinforcement (Dwarf Stance, lightning field) and immediately use Echoing Eruption (Mace 3) can create 2 blast finishers and double swiftness gain.
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Another similar bug:
First use Inspiring Reinforcement (lightning field) and then use Searing Fissure (Mace 2, fire field) can be blasted together with Echoing Eruption (Mace 3) and create 10sec. swiftness and 20sec. 3 stacks of might. Note that the opposite order of the fields doesn’t blast 2 fields; it has to be IR first and SF next. I tested other blast finishers, but they can only blast one of the fields.