It is possible to use Symbols instead of strings, which yields some nice improvements in terms of no longer allowing construction of actions with potentially misspelled strings, etc.
You link to a comment which indicates serialization is a potentially breaking issue. This is a tradeoff that does not affect the routine behavior of redux but may affect advanced use cases such as allowing user upload of action history for bug reports.
Regardless of serialization/replay-ability, the core of the suggestion is to `import` some constant instead of using raw strings. Symbols have the benefit of forcing an import, whereas a list of constants that reference strings can be "bypassed" by writing the correct string in a random file. In fact, the redux actions documentation uses the following example of this pattern as the first example.
```
// fileA
const ADD_TODO = 'ADD_TODO'
//fileB
{
type: ADD_TODO,
text: 'Build my first Redux app'
}
```