Malicious QR codes were used to establish a separate device as a ‘linked device’ which would allow the attacker to receive and read Signal messages sent to and from the target

Fair enough. I tried HeliBoard because it was recommended and stuck with it. I don’t use voice to text, but got swipe texting to work on HeliBoard

What are your thoughts on HeliBoard compared to FUTO?

Try Molly instead which is a hardened fork of Signal. Molly uses the same servers and is transparent to the operator.

You can install Molly through F-Droid or Accrescent.

In depth review validating the credibility of Signal’s encryption by a Security Engineer who specializes in encryption.

Reviewing the Cryptography Used by Signal by Soatok

The bottom line was in total, no vulnerabilities were found.