When responding to reactive text messages the agent signature is stripped from the message. However, proactive messages do not strip the signature.
It would be nice if proactive text messages didn't require us to remove the agent signature so my agents could effortlessly move back and forth between proactive and reactive messaging.
I reached out to Zendesk's support about this and their explanation was that this is just a function of the product and recommended making this suggestion within the community.
From Zendesk support:
"A feature of inbound texts will strip the agent signature from the text. However, because you have to use a trigger for proactive texts, there's no way around excluding the signature. He also said he thinks your best option to work around this would be to apply signatures manually to ticket comments through a macro"