Definitely no luck with the homebrew heated platform. The 10 ohm nichrome wire pulled about an amp of current (not surprising for a 12 volt power source), but took 10-20 minutes to heart up. I poked a wire into the silicone between the layers of glass and dragged out the middle of the wire, and soldered a new wire on. By connecting the new midpoint to one terminal and the original two wires to the other terminal, that meant I had two wires in the platform that were half as long, and it drew (not surprisingly) 4 amps... and started heating the plastruder circuits too much. (It heated up really fast, though!) I then just connected up one side for 2 amps of power... and the glass quietly cracked.
Next step: two amps of current seemed ok for the plastruder, so if I remake the build platform (and try glass again), I'll try stretching two 10 ohm / 16" nichrome wires inside. The platform can definitely use the extra nichrome to spread out the heat source and hopefully keep the glass safe.