Aren't the tiles mostly used to plan the cosmology? Prior to the final battle, I mean. (They have the planes' power-description on them, and implies the PCs know how they work.) The only way for the PCs could get ahold of the those three icons (Jiquus, Regulus, Patricalus) are by bum-rushing Nic and taking them off his body in the final fight. They shouldn't necessarily know what are those planes' powers (or even their elements).
What I'm wondering is ... what benefits do these things give when worn as amulets? The original planer icons in Act1 (Urim, Apet, etc) all gave you fun little abilities. Here's an opportunity for about two dozen unique magic items! (That you can even carry from the Gyre back to Lanjyr, across the soul-splits!)
This also makes me want to seed in some planar icons as treasure in adv7, during the ObCon. Heck, they were clearly using Watchmaker powers back then to make their demo-rooms: they surely had a Patricalus and Regulus icons at the time (though the latter would not be useful to the PCs, given that that particular "scroll of fate" would just talk about a minute's worth of time). Hrm.