I had exactly the problem described in Reload SQL editor file, but even after I knew the feature existed I had to read through the 7.1 release notes to find it. It's called "File > Revert to Saved". I have always used this as "go back to old version", so I did not realize it would also work for "refresh from version on disk".
I couldn't find this feature last year (I googled "dbvisualizer sql commander reload from saved", just like the feature request thread title). So every single time I generate SQL with Python I had been doing this:
I think if it was an option, I would do as I have done in Notepad++ and have files auto-reload when they change on disk (or at least ask me if I want to).
At least this post may help people Googling for the feature to find out it exists.
We will look into this in an upcoming maintenance version.