Another thought: Since you have more pain when your elbow is bent, can you lower the keyboard so that your elbow is significantly more straight? You will need to place the keyboard in a negative tilt (far side lower than front) to keep from extending your wrists. And if you are long armed and long legged it may be challenging to get the keyboard low enough without hitting your legs. IF that is the case, you might try a standing station or keyboard tray that allows you to stand up. (Be sure to raise the monitor, too). A sit-stand stool would give you some relief from the standing and still keep your legs out of the way. If the angle of the negative tilt is so extreme that the keyboard slides, add a Rubbermaid mat. C.Kelley
You mentioned ergo keyboards but not which ones. You might benefit from a larger spread to the alphabet keys or more extreme tenting, like with the newer Kinesis Freestyle. You also might benefit from a neutral posture mouse like the Evoluent.
In defense of PT: PT is not just about ROM and strenghening. An experienced PT will look at the entire arm, shoulder girdle and upper torso, not just the elbow. There may be scar tissue that needs to be broken up with deep tissue work or modalities. You may not experience pain when you work out, but that doesn’t mean your technique isn’t contributing to your problem. A PT can evaluate your work out methods and determine if changes would help. Find someone who specializes in body work and RSI.
You might benefit from an ergo evaluation where the evaluator watches you type. Static posture can be as damaging as repetitive motion. You may also hit the keys too hard. A light touch keyboard like the Goldtouch or Kinesis Freestyle might help.
And if you aren’t already, make sure you stop keying every 15 minutes and move your shoulders, arms and hands for 30 to 60 seconds.
The voice recognition software is also a good idea.