I really enjoyed your story!
Even more so because it was true!
I have used the technique of needing light to operate a combination lock a number of times. Daylight is an obvious one, but you can also set a lamp on a timer to let you out sooner. Something on my "to do" list is to create a random timer where the lamp will turn on only for a minute at random times. Best be ready or you will miss it!
I have also confined myself in a dog kennel. Just as you described, using Zip ties to prevent me from simply sliding the long rod out that hold the sides together. I usually do my bondage naked and discovered that having any skin touching the metal frame can get COLD!
I look forward to hearing more about your self bondage scenarios!
Ron