I have never owned a crockpot or a yogurt thingy. Poor me But since I have had my TMX I have made lots from the EDC without a failure. I just cook it and dump it into my Thermoserver overnight and in the morning I have lovely creamy yogurt which I just put in a plastic container on the fridge and it lasts for weeks. When it is getting low I use that yogurt as a starter.
I would give it a couple of batches before I added anything to it to try and thicken it and see if it happens naturally as you improve your starter