Btm or wtm Eating after shipping

Hi members
I’m new to black throats and I’m looking for some general info.
I’ve read that after a baby/juvi are shipped, it’s hard to get them to eat. I’ve read this on a couple occasions and not sure how true it is. Recently, A Jersey jerk went off on me because I didn’t want to buy HIS btm in Jersey and I found one in the south.
He persisted it would at min, give me a hard time eating after being shipped.

Is this true? If so, anything I can do to get it to eat again? Is it recommended that I do a pick up or will it be fine to ship. Can I take a 18” baby and put it into his huge home made enclosure? With beardies, sand is not a good thing for them as new babies. Is a btm the same? Can it be put on substrate from the beginning? I am looking up all info I can before making a decision on getting one. They are massive and I want it to be comfortable and well taken care of.

Thank you
Rich