That was my main concern with the idea, someone who has no idea what they are doing throwing one on a device that can't handle the power levels. You could laser engrave a warning on the side of the carto in hopes that a new vaper would see this giant warning and think twice before putting it on their device. Either way though I doubt the Chinese care about that type of thing at all, and they are the most likely to mass produce something like this.
The wicking ability of the filler material could be an issue as well. I think it's possible that the filler would keep up just fine, when you consider the amount of juice hanging out inside the filler material directly surrounding the coil is massive compared to the small amount of juice available inside a silica or mesh wick.
Commercially available wick-based systems have always had more issues keeping up with my vaping than my cartotanks ever did in my experience. While I've never had issues with cartos keeping up, I can't say the same for wick based systems. My silica RDA builds don't have issues keeping up, but that's not really a fair comparison since those are drippers which are basically swimming in a pool of juice anyway.
It is very possible the filler material wouldn't be able to keep pace but I don't think it's a foregone conclusion that the filler wouldn't work.
To get away from the filler material they could always do something like the CE-style cartos but using SS mesh and an SLR coil. Have a vertical mesh wick inside the carto, have the coil at the top, and holes around the base of the carto body to allow juice inside the carto.
I'm getting really off-topic now, sorry, I just really like the idea of an SLR carto