So once it has been saved to local storage, you can't edit the Title nor the Description on the iPad. You have to upload it to the website before you can edit it. Do I have that right?
Yes, that is correct. Whatever you enter into those fields after a download is saved in the logbook file on your iPad and/or in the upload to the web log. There is no edit function for the logbook on your iPad. Think of it mostly as a local way to temporarily save that information until you upload it.
The actual saved files, to which the logbook entries point, are the same as the .csv files uploaded to the online log and contain the same data. They do NOT contain the title/description.
I have also found, when I got a new iPhone last November, that the logbook, but NOT the data files, is lost. My logbook on this phone only contains pointers to files downloaded after I got it. But in the Files app, the Flightsketch folder contains all the files I have saved locally to my phone, including the one before my current one, for a current total of 863 files. My prior iPhone was the one I had when I first started beta testing the FS Mini in 2019, which was before there was a logbook function in the app.
If you don't save locally, then there won't be a files accessible through the Files app on your iPad (or iPhone).
My usual flow is to download the data, rename the file to include the model name and flight number (replacing the timestamp portion of the default name), put in a title (model and flight number( and usually the motor used in the description, then save both locally and upload to the web log. If I'm flying where I don't have cell coverage, then I use the logbook function to upload to the web log as soon as it is practical.