[Mistwalker]

If technomancers get cyberware and their essence drops, let's say 2 points. Does their Resonance drop?

I can find wording that says that the Magic attribute drops when Essence drops, but nothing about Resonance

[Michael Chandra]

Errata say yes:

p. 38, Essence, paragraph 1
The following changes are made to this paragraph
for clarity:
All characters have this attribute. It functions
as a capacity rating for how much cyberware,
bioware, and other augmentations characters can
hold. The metahuman body can only contain so
much ’ware before it loses the small spark that separates
a living being from a machine. This attribute
primarily exists due to the degrees of difference between
biology and technology—it simply does not
flow well through technology and becomes limited
as your Essence declines (specifically, anytime your
Essence goes below any whole integer, you lose a
corresponding point of Magic or Resonance for
each integer passed). Also, some magic, particularly
healing magic, has less of an effect on you as you
gain more augmentations.

[Mistwalker]

Thank you