I think the ROK needs to pay attention to this threat because the balloon activists are giving the Kim regime the rationale to launch a provocation:
A North Korean propaganda outlet on Saturday lashed out at defector groups for sending anti-Pyongyang leaflets, warning of a reaction that could go beyond the explosion of an inter-Korean liaison office two years ago.
The Tongil Shinbo, a weekly North Korean publication, also criticized the Yoon Suk-yeol government for speaking out about human rights in North Korea and seeking the denuclearization of the Korean Peninsula.
There could be an action that would exceed the blowup of the liaison office in its border town of Kaesong on June 16, 2020, if North Korean defector groups continue to send goods and leaflets to the North, the newspaper said.
Yonhap
You can read more at the link, but I find the anger over the balloon activists ironic considering for decades North Korea used to be the ones sending propaganda balloons into South Korea. I am old enough to remember when they used to do this and when the leaflets were found we had to turn them in and could not keep them.