lemonhaze ...
Congratulations on your purchase. You're going to love the effect and improvement in SQ. I know your question was about placing the E Mats into your circuit breaker but have you tried pasting your connections with the TC yet?
On the circuit breaker ... I haven't moved the two mats that were placed in the circuit breaker a few months ago, so I can't speak for that exact location. However, I've moved mats around from component to component over time, even loaning them to friends for listening sessions at their homes, and haven't noticed a substantial degradation in sound. I don't think a few hours would make much difference. At any rate, even if you left them off for days, and had to start from scratch, the improvement is almost immediate ... with a significant improvement over a day or so, even a half a day.
Take care ...
Frank