Somewhat ironic that the 'one and only assault tree' does not in fact have the highest number of Offensive Actions under theirAs the one and only assault tree i welcome you brother of my spirit.
So the formula is: n * (1 + 0.1 + 0.4) * 2 = 3nClarified the 'Expand the Forest's Reach' action to indicate that it's additive with other sources, rather than multiplicative.
The Worm's bonus is always multiplicative, so this comes out to a total multiplier of *3.