@RichyTee 

Hi, you want to make the pair button useless, right?

When your children holds it, the PLC unit has no change?

I am afraid the requirements can't be achieved.

Since there is no setting can make the pair button useless, the pair button can not only be used to configure the powerline device, can also be used to reset the powerline device.

As for the Security level, it is not related to disable the pair button.

Our powerline units support HomePlug standard.

There is one method to configure the powerline unit is to make the same secured network name for every unit. Then all the units which have the same network name can connect each other.

Hope this answer can help you.

Good day!