Looking into this a bit further, a perfect work-around would be if I was able to change the "Send Using" on replies -- but I can't seem to do that.
It looks like you used to be able to in old BB versions, but they dropped this.
There was a program called "BBReply" that would let you override this, but it's quite outdated and I'm not sure I want to try it on a newer model.
Any suggestions? I pay for an app if one existed.