My mom worked at the IPP which built the mentioned Wendelstein 7X - a stellerator - but she was not into physics. In this video he doesn't explain well how tokamaks are different from stellerators. To my understanding, stellerators are tokamaks with twisted coils and as coils in a stellerator are so twisted, you can't easily swap them if something breaks while in the much more symmetric tokamaks, you can have them manufactured in for example 45° segments and keep a stock of one segment for fast replacement.

Who can correct me here?