But if it keep the way it was tested about refreshing Flame Shock, then Echo of the Elements will actually be detrimental to use with Flame Shock, outside of multidotting, but with Lava Lash spread even on this case will not be very good to use the proc on Flame Shock.
Edit: Another question, is Liquid Magma considered a spell, is it buffed by Unleash Flames/Unleash Elements?