I hope I'm not too late in getting a response to you.
My advice in this situation would be to let them fulfill the delivery requirement. Normally, it would be ideal for the unit to gradually move to room temperature, and if it was mine, I might insist. But I don't see any particular reason why a quick power-on would cause any damage to the unit.
If you can avoid it, I would. But if you can't, it's not likely that the unit will suffer long term damage as a result.
My new Samsung 46LN750 will be delivered tomorrow, purchased from Amazon. I believe I read somewhere that the delivery people are required to unbox the TV and plug it in to make sure it powers up.
Since the TV will probably be very cold from shipping, I am wondering if it is considered safe to power it up while it is cold? And, if I chose not to allow this, would that then become a warrranty issue if there was a problem which I did not discover until after I let it warm up and then plugged it in?
Would appreciate your advice. Thanks.