Can they work on the spasms and check for trigger points in the muscles? Or does the touch and pressure bother too much with the RSD?

If you have trigger points in the muscles they can't fully stop spasming until the TrPs are resolved.

TOS gives us severe spasms too, many get horrible headaches. It just sounded so familiar I had to mention it.

I remember the time I had really bad spasms -neck/chest & upper body, ugghhh, misery.
Felt like I could not turn my head, felt like I had tight turtle neck sweater on all the time and a metal vest.
Riding in a car on a rough road , or even the stops /starts my neck was so fatigued but I could not get it to relax. i had no clue what was going on back then...

My chiro and helped me with the spasms and a really good PT guy found that my top ribs had got raised up and was kind of stuck against my collarbone.
This was increasing my hand/arm symptoms , limiting my hand use as well as stalling my recovery progress {RSI/TOS}.

Anyway this PT guy pressed downward on my top rib/shoulder area and it dropped down to the normal place - he did one side at a time so we could compare the differences, it was a good inch lower - so he did the other side and I felt so much better..
I was able to drive 40 mins home with no hand /arm pain.

The spasms had been so severe that they pulled my top ribs up and they just happened to stick there and not drop back down on their own.
Partially because I have some hyper mobility of my joints.