For our add-in, we need some data that will be different on a per-customer basis, such as a customer ID, base URL (changes based on region/environment), API key, etc. We will need this data in order to contact some of our external microservices.
We've looked into RoamingSettings, and that seems to be a good way to save this customer data for later use, but this would only be possible AFTER our data gets injected and is available to the add-in for saving.
We've looked into this question and its corresponding answers: Read parameters from Outlook 365 Add-In manifest. Michael Zlatkovsky's answer, regarding appending an encoded string with that data to the add-in's start URL in the XML manifest, and later grabbing that URL with JavaScript and decoding/parsing that query string seems to be our best option yet.
Is there a standardized or more common way of injecting data into an add-in?