I've been in a lot of PT with repetitive motion injuries over the years, none of my PTs ever told me to not worry about pain...
If they did I would have found a better PT place.. not all PT's or places are the same..
You can find better ones..

And if it is RSD, getting the correct kind of PT is important..
Don't settle for substandard care, or even worse, treatment that might worsen things..