Based on prior comments made by LWD, as I mentioned in an earlier response, the difference between Copying and Import/Export is the preservation of IDs.

Copying a Realm creates a new Realm with the same Topics/Articles, but they have new IDs. Exporting and Importing preserves the existing IDs so the Topics/Articles can be updated with future re-Exports and re-Imports. As Farling mentioned, I do not think it is particularly wise to Export and Import back and forth in both directions between two (or more) Realms.. having one master Realm that you export from and import into others seems more stable (less prone to accidental errors).

A template Realm for modules sounds like the appropriate place for using Copy. Make a Realm that has the structure you want, then Copy it to create a new Realm for each module (assuming module is one Adventure) and then populate the Topics/Articles as needed.

If you want to propagate content (rules or story elements), you have two choices.

1) If each is to be a stand-alone version for running a group through them independently, you can Copy the Realm to create that stand-alone version. Updates to the original will NOT propagate to the copy, and later exporting elements from the original can create duplicates if imported into the copied Realm.

2) If they are somehow not meant to be stand-alone, or you want to apply further updates from the original to the spin-off Realm(s), then Export and Import seems more appropriate. Again, bi-directional Exporting and Importing increases the chances of messing up the original, so I don't recommend it (even if, in theory, it should work).

Once you have a Realm for each module (or for rules and background setting information), to *combine* them for actual play, that's limited to Exporting from the source and Importing into the destination, where the destination is most likely a new, empty Realm for that purpose.

I think I can help here. I currently have 4 realm templates.

1. Blank - Completely empty. ALL default categories/tags are disabled or deleted.
2. Structure - This contains all the categories/tags all my realms use. I don't use any of the defaults.
3. Gamesystem - This contains all the game specific categories/tags my realms use, PLUS the import from Structure.
4. World - This contains all the world lore etc. that all my realms use, PLUS the import from Structure.

When I want to create a new realm, I first COPY the blank realm.
Next I open that realm, and import a STRUCTURE-ONLY export from the Structure realm.
Then I import a FULL export from the World and/or PF2 realms.

ALL imports require using advanced options and checking the boxes for OVERWRITE conflicts.

ALL exports have "preserve ownership" checked. This is super important.

If you try to create any topics in the totally blank realm RW WILL CRASH. Make sure you have some sort of category for every possible section.

If I make a change to any of the template realms and re-export, all my changes easily import to my active realm.

Example:
Partway through creating a realm, I realized I needed another snippet in a category. I saved and synced my current realm, switch to the Structure realm, and made my change. Exported preserving ownership, imported to my current realm overwriting conflicts, and the category now has the additional snippet. Any previously created topics require a resync or manual add to get the new snippet, but all newly created topics afterwards have it.

It took quite a bit of trial and error to get this all to work, but it was well worth the effort.

This is extremely helpful, nightpanda. I've been struggling with the best approach to this myself - thank you for your input.

Thank you Silveras/Nightpanda! Your help is appreciated!

Thanks you guys for the detailed procedure.

What will be even more helpful is if LW will publish a truly empty template.
One that has nothing to turn off, that can be used as a base.

Oo! Not a bad idea. I'll pass that along!