Hey Fen,
Really great stuff! Was looking for something quick like this I could use for my game to generate some randomness.
I’m trying to reconstruct your tutorial and implement the Growing Tree algorithm into my game, but I wasn’t able to finish it as I couldn’t find any documentation for the “Check and Set” function inside the “Set Opened” function. Did I miss something? Right now my generated maze doesn’t have any open area , just a grid of interlocking meshes. I am guessing it might be because of that function? Still trying to understand everything.
The link to download the blueprint is broken as well on that page so I couldn’t see from that 
any chance you have a copy around still?
Also I was curious any reason why you switched from the Binary Tree Algorithm to the Growing Tree Algorithm instead?
Thanks for this and any help you can provide!