Maybe I was just being stupid before, but I managed to get it working with Ionic File. Thanks to akshukla07 for giving the only source I could find that explained usage.
If anyone has a source that explains how Ionic File works with Android and iOS app filesystems I would hugely appreciate it!
setupQuestionService() {
this.file.readAsText(this.file.applicationDirectory + "www/assets/exams/oral", "oral-template.json")
.then(res => {
let data = (JSON.parse(res) as any).questions
for (let dataIndex=0; dataIndex<data.length; dataIndex++) {
let newQuestion = new OralQuestion(data[dataIndex].module, data[dataIndex].section, data[dataIndex].questionText, data[dataIndex].answerText)
this.questions.push(newQuestion)
}
})
}