Toms, yes, for that reason. Other things I put in, right or wrong, as deep as I can to give them support, especially brassica. With lettuce, I try not to bury any seed leaves, in case they rot. Leeks, of course, I drop into a 10" hole.
So much depends on how well the plant has grown in the pot - leggy or not? Well. that's my offering! = Tim