This works with ti, however I would not try it with ceramic as like you said it will most likely crack. A common method some users and I previously have used is dropping the dab in cold then heating until you see smoke from your ti cap airhole, get the low temp dab, then heat it up again and repeat for higher temps. I do not think this would work in your situation however, just due to the heat transfers between ceramic being so slim on easily cracking. IF you're looking for a quartz banger cap just use a marble in the meantime, and if you want to bust out the bank go ahead and grab a cap made for them
http://www.ebay.com/itm/Halen-Honey-Hole-Quartz-Carb-Cap-Dabber-/171617998268
I cringed reading this LHS tip and at the people supporting this/believe it is safe. I have had silicon pieces of my pads come off from using my ti tool (albeit aggressively) and vaporizing even a little bit of silicone would most likely outweigh any health vaporizing benefits, not to mention the pads are not tested to withstand such heat or function as such. If you are talking about using it as a honeybucket cap, there is even more heat touching the silicone as the arm will also touch and possibly melt your pad. (releasing gasses I'd assume, not quite what I'd like to inhale). IMO if youre capping your rig unless you are completely out of options use the same material as your nail for your cap. Some nails just can't be capped like the quartzcastle (to an extent) and your best bet for those situations is either sucking it up and doing full temps, or a mediocre cap with a quartz or glass (if youre really on the low budget).