There are variables assigned to the weld symbols. I am sure these are meant to be picked off the weld features and they may accurately show as dual dimensions.
If you are overwriting these variables, you have little option. You can either add the text you want on a single line as in:
1.0 [25.4]
or you add disassociated text and type it in yourself and then relate it to the view so it at least moves with the view.
You will find that many of the weld symbols are poorly set up for dual dimensioning. Unless you have specific instruction by policy to make everything associative, you will find yourself cutting corners around weld very quickly.