I have spent the last 2 days troubleshooting and trying to code a solution for this, mostly with AutoHotkey, but all of my efforts have been futile. One problem leads to another. If you total the overall amount of time I've been looking for a solution for this, it comes to about 10 months.
To be honest, I think it is a bit silly that there is not a feature to allow for two or more PTT keys. Open-mic is not an option as there is lots of background noise around my setup and I need to be able to record in-game voice and Teamspeak.
Seeing multiple PTT keys in the changelog would make me incredible happy.
If YOU also want multiple PTT keys, comment on this thread saying so.
PS. Yes, I do know that there are already a huge amount of posts like this, but if we show that we want this feature, we will probably get it!