Perhaps there's a way to have the materials show up on the Quick Menu in Challenge Mode and not in regular play? (Ie. an in-game command.)
Regardless, it was irresponsible for Sega to have something so irreversible (at least back then) be so easy to do with one wrong press of a button. Typical of their lack of foresight. At least now we can reset materials, but that still causes you to lose all of them.
This isn't for myself, BTW. All of my characters have 100% perfect mat plans and are finished, but I did intentionally refuse to use any of my secondary characters until their materials were 100% finished due to this. A very unfortunate yet necessary precaution. It would be nice to not have to worry about this.
This brings me to another idea:
I fully agree that the full mat reset should cause a loss of all materials (save HP and TP) since it's very forgiving. It also creates a good "wealth sink" for the game. HOWEVER, it might be a good idea to add a shop or a quest that allows you to remove say, one or two used materials at the cost of a PD. That way, if you accidentally eat ONE wrong material, you don't have to do a full mat reset and lose 50 PDs (or more) worth of mats.
Thoughts on this?