I think the video is https://www.youtube.com/watch?v=l8YVh0O1aFA, he linked the channel but not the specific video. There does seem to be some actual testing there

these maces were ceremonial because he assumed they'd make poor weapons

I think the point was that they're poor weapons against plate armor. Fortunately for mace-lovers, most people on the battlefield aren't fancylad aristocrats who can afford a full suit of quality plate so they can get bonked just fine (especially outside of late-medieval Europe, which he brings attention to toward the end - maces were extensively used in other parts of the world, and even for Europe he points out that a lot of the surviving historical maces and artistic depictions from them are actually from the 16th century, at which point armor coverage of the average soldier has decreased somewhat).

It's kind of a clickbaity title, but I guess "flanged maces in the very specific and limited period of 14th-16th century Western & Central Europe" doesn't roll off the tongue as nicely