MT,

I'm at a loss for an explanation to your predicament :-/
dd, is right, you have to go with what you have confidence in.
I don't even tie a knot after the cord-lock.
The idea behind them is to eliminate loops and make for a quick/secure way to cinch on your combat boots if you are awakened in the night with hell raining down on you.

Once I got them working properly, I cut my laces just long enough so when I slide the cord to the end, I can get my shoe/boot on/off easily.
I did tie a overhand knot in the end of each lace, so I wouldn't accidentally pull the cord-lock off.

The free end of the laces once the cord-lock is secured, is about to the end of the boot toe. Nothing to snag/snarl.

I'm interested to see how Jimbo makes out with them?
dd's minor modification with the bow-tie knot is fine as it provides the security and peace of mind you want, but the product was designed to eliminate tie-ing knots period.

 Maybe with there being their mass produced, with the small size and design, it might be a production quality issue, not a design flaw?
I hate to think anyone spent money, no matter how little on a product I recommended and have it be crap, at least for them :-[