I can't really smell the rat when thawing/heating it.
But I don't have the greatest nose thanks to smoking like a chimney in the past.
He definitely can, and comes out to watch me through the glass until I get up from my thawing spot to offer it to him.
Just bear in mind they also rely on the heat of the item, so keep your hands clear of it and make sure the head is warm to your touch. Combining all that knowledge should allow you to be feeding your BP with no problems.
Thawing a twilight when they're already waking up also helps.