I know they look and sound scary - AJAX, JSON, ARRAYS, OMG!! - but they are really not!
Just start using them and you'll see. Download a few examples from the tutorials section, try changing some bits. You only need two or three lines of code to load something with AJAX, you don't even have to understand how it works, just copy them from someone else's project.
Same with JSON - all you need is Array.AsJSON expression to convert array to string, and "Array load from JSON" to convert it back. Two lines of code! Again, you don't need to know anything about JSON, its format, structure etc.
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You can save individual variables to Local Storage if you wish. But to save/load 20 variables you will need like 60 events!
To save/load an array or dictionary with the same 20 values, you will only need 3 events. See what I mean?