For me biggest missing I’ve found is web/external queries. Excel has a system to log in to an API, retrieve that data and format it before it lands on your sheet.
Libre functionality here is lacking/non existent.
My workaround was to write a python query, add it as a cron job, write that data to a csv then call that csv from my sheet with a timed refresh. Not something the average user can or wants to do.
Everything else I’ve found achievable.
If you’re heading to Sideburn, get the dust app. (If you haven’t already). https://dust.events/docs/intro/ (link for Android or iOS app is here).
It is an app (for burning man & regional events) that has details of theme camps, art, music & the events on during the festival. They may have a paper guide and the app can be more up to date.
I recommend having a look through the events so you have the option of preparing for any you require something specific for (like a particular color clothing etc). The app doesn’t require internet access after retrieving the event data if you don’t have reception at the location.