As far as I can see, the app is missing a very critical function of being able to share tasks with multiple project from the app. In essence if I want to add another project to a task I would like to do it from the app. Could @Alexis or @Matt_Bramlage confirm this.
Hello. This should actually be possible in the iOS (and Android) apps.
When viewing a task on iOS, click the pencil icon to enter the edit view. You will see a button to ‘Add Project’. From there you can add additional projects (one at a time). See screenshot below.