How to disable parallel build in Ionic Capacitor Vue3 project?

As noted here, there are issues with vue-loader when using the <script setup> syntax in Vue 3 SFCs.

I’m set up with a plain Javascript project (not Typescript) and I can’t work out how to pass that parallel: false setting to be used during the build process. I’ve created a vue.config.js file with module.exports = { parallel: false, }; inside, but it doesn’t appear to work. I’m still getting the following error during the build process:

error  in ./src/pages/user/Login.vue?vue&type=script&setup=true&lang=js

Module build failed (from ./node_modules/@vue/cli-service/node_modules/vue-loader-v16/dist/index.js):
TypeError: Cannot read property 'content' of null
    at Object.selectBlock (/Users/admin/Code/ionic/my_project/node_modules/@vue/cli-service/node_modules/vue-loader-v16/dist/select.js:25:45)
    at Object.loader (/Users/admin/Code/ionic/my_project/node_modules/@vue/cli-service/node_modules/vue-loader-v16/dist/index.js:57:25)

 @ ./src/pages/user/Login.vue?vue&type=script&setup=true&lang=js 1:0-329 1:0-329 1:330-648 1:330-648
 @ ./src/pages/user/Login.vue
 @ ./src/router/index.js
 @ ./src/main.js
 @ multi ./src/main.js

Any ideas anyone? I could refactor without the <script setup> syntax, but I really don’t want to since it’s so much better being able to use export from for components.