Caps form up in a matter of seconds after being powered up. If I recall, there's a formula you can use to determine the precise time it takes. As far as I know, resistors and chips don't need any time to form.
Instead of endless debate, have you ever wondered why manufacturers don't burn in their amps prior to purchase?
If burn in is so essential, then why not stick it on a rack for X amount of hours before shipping it to the customer? If anyone is planning to buy an amp that requires burn in, ask the manufacturer to burn it in for you.
If the manufacturer insists that it has to be burned in with your music, etc., etc., ask if you can get a refund if the amp is accidentally burned in the "wrong" way and doesn't sound good as a result.
Go ahead. See what happens.