you would need to set “WPPizza-> Order settings->Items update style” as well as
“WPPizza-> layout -> miscellaneous -> accordion style” to

“a (themeroller) style is already loaded / I provide my own style”
and provide your own style/css somewhere (or not)

As of 3.18.1 the plugin also includes a localised version of the “smoothness” css (named “smoothness.gdpr” as an option in the theme dropdown choices ) you could select instead.
However, there will not be any other localised versions of any of the other themeroller themes so if “smoothness” is not what you are looking for but still want to load a localised version , you will have to provide your own css as outlined above

just mentioning it here for completeness sake , in case someone else has the same requirements.

The downside of this is of course that this local version might not always be the most recent style you would otherwise get when using the external css file hosted by jquery.com….

A decision the user will have to make in the end . I’m just offering the option now….