TL;DR: just thread the extra laces down between the tongue and laces, bring them back up the other side if necessary. [See picture] I’m frugal, and I had an incident where I put lock laces on a pair of shoes too quick, had to return for a different model with a roomier toe box and I went through the painful process of unclamping and re lacing the lock laces without the plastic ends.

https://www.amazon.com/Lock-Laces-Elastic-Shoelaces-Size/dp/B07XB37ZRT