New top tip from me, just started doing this and it is a big help.
For FGU, make yourself a map module.
Collect together your maps with line-of-sight information so that you can import them into any campaign you subsequently run. I started doing this because I'd want to use the same map for different games in different systems and didn't want to have to re-enter LOS info each time.
Do this:
1) Make a new campaign with nothing in it (no modules or extensions, using whatever ruleset). This will be the place you ALWAYS do your map imports.
2) In the Images and Maps tab, make a new category. I use "Hywel's Battlemaps".
3) Import the maps you want. Enter the LOS information here, set the grid, etc.
4) Export the module with "/export". Choose a suitable name for the module ("Hywel's Battlemaps") and export only the images and maps info.
5) Find the .mod file in your SmiteWorks modules directory.
6) Rename to .zip
7) Unzip it
8) Edit the definition.xml file, changing Ruleset to Any.
9) Rezip the module directory
10) Rename back to .mod
Now you have a universal module that you can load from any one of your campaigns containing all your battlemaps with LOS data. When you load your other campaigns, your map module should be there ready for you to load in.
When you do so, you will want to populate the maps with encounters, pins, etc. specific to that campaign. I like do that by dragging and dropping the map from the module "master" copy back onto the Images and Maps window, which gives you a map copy local to that campaign. Then you can add all your system specific stuff to that copy of it and can always go back to the pristine module version if you need to (e.g. to run a new encounter in the same place).
You have to repeat steps 3-10 to add a new map to your map module which is a little bit of a fiddle, but far easier than loading up a map you know you entered LOS for for a Savage Worlds one-off when you want to re-use it for your regular 5e campaign. The time consuming bit is entering LOS for maps you've made externally, and this lets you reuse them without that time-consuming step.
It was probably obvious how and why to do this for old hands, but it wasn't for me. So hopefully this will help.
Cheers, Hywel