The bed clip supplied with the Kossel Mini kit from HKbay.com (and others?) is not able to accomodate the heated bed upgrade since the extra layer of silicone makes the bed too thick to fit into the clip. I tried to file a bit off the original clips and failed miserably, so I ended up printing new ones.
With a simple change done in tinkercad, the clip finally works again!
Fits 190 mm circular borosilicate glass bed with 170 mm circular silicone heatpad.
P.S. I'd like to give credit to whoever designed the original clip, but couldn't find it anywhere except in the files supplied with my kit - please let me know if you know the original source :-)