Ah, got it sorted thanks to this: https://forum.quasar-framework.org/topic/6135/passing-more-information-and-or-event-from-q-select-on-change-input/9
Final solution:
<q-form @submit="onSubmit" class="q-gutter-md">
<div v-if="questions.length">
<div v-for="question in questions" :key="question.id" class="row">
<div class="col">{{ question.text }}</div>
<div class="col">
<q-select v-model="model.questions[question.id]" :options="question.answers" use-input use-chips multiple label="" option-value="id" option-label="text" @add="add" @new-value="(value, done) => { createValue(value, done, question.id) }" />
</div>
<div class="col">
</div>
</div>
<div>
<q-btn label="Submit" type="submit" color="primary" />
</div>
</div>
<div v-if="!questions.length">No questions found</div>
</q-form>
and
createValue(val, done, questionId) {
console.log("questionId", questionId)
done(val)
},
