EUTR1 submitted - how to get formal approval for right to remain

[GeekyPete]

I'm an EU national living in Ireland and we're in the process of getting residency for my non-EU wife who's now in the country with me. Following the new COVID guidelines we've submitted the EUTR1 application and supporting documents via email and the next day already got a reply confirming receipt and it said she will be able to remain in the state while the application is pending and asked to submit the paperwork by registered post.

I assume my wife's right to remain needs some formal paperwork, will we be getting that? She currently has until mid January and would like to avoid her needing to leave the country.

Do we need to get an appointment to register for the first time at the Burgh Quay registration office (I've been reading how difficult it is to get those) or is there a separate COVID process now? What happens if we don't manage to get an appointment before January?

Thanks for any tips and information on what are our next steps!