For all snake enclosures:
Step 1: check for points of escape. This is any place where the enclosure is not completely connected. In the tutorials you posted, the only point of escape is through the lid.
Step 2: make sure the points of escape are firmly anchored and cannot, under realistic amounts of stress, be opened by the reptile.
From the sounds of it, you should be fine, but honestly I'd swap from bungee cords to a set of clips on plastic fabric (like the kinds used for backpack straps). The reason I suggest that is because it's really easy to secure, allows little to no give, adds almost no stress to the enclosure, and is very easily visually identified as attached/open. I used them on a tank before and I honestly cannot oversell the things. Plus the plastic fabric and clips are pretty cheap