One of my previous Water monitors was reasonably "calm" from day one, though he had been in the petshop for a couple of months, I suspect they did force handle, and obviously there would be people glaring in the tank for that period, too.
I wouldn`t get into the habit of feeding from your fingers, I can tell you if you get bitten when the monitor has grown another foot or so it will hurt quite badly and that pain and damage increases with size!
Edit: You previously mentioned the SV length was 4 inches and the tail length is 3, is half the tail missing, because it should be around 6 to 7 inches long (and that would still be a very small hatchling size), they can measure between 12 to 15 inches ToL?
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