First I've heard of this one. I never got into Inform7 because I didn't find the language very discoverable; it felt like writing AppleScript. Do you know of any links to larger examples of Dialog code, like a full open source game written in the language?
That was my frustration as well; and it comes up in discussions. Simple to medium complex things are easy in Inform7, but when you start hitting the edges, you find out that its expressive English-like syntax is in the uncanny valley and exactly how you phrase things becomes vitally important and difficult to discern, even from the mounds of documentation it generates from your story file and from the standard library and extensions.
The creator of Dialog, Linus Åkesson, went ahead and used it to create the winning entry for the IF Comp 2019. Does not look as if the source code was published, but I think winning that contest is the best indicator that a language for I-F is good enough to use in practice that I can imagine.
