Requires running a native app outside of the browser for unexplained reasons. The app is closed source so can't be audited. Extensions with such high abuse potential should be banned from AMO.
Edit: the developer answer is just blowing smoke. AMO does not check external software. Virus scanners only check against known signatures. Code signing only allows verifying the author.
Native app is only used for merging streaming type video segments with help of included open source FFmpeg converter. Please note that add-on passed AMO verification and native application have digital signature to provide secure. You can check it by any anti malware soft in case of suspicions.
