I'm assuming by that you mean racking a second time? No problems, as long as you're willing to take the risk of oxygen in your beer. See, what's often called "second fermentation" isn't, really. Your beer really isn't fermenting after primary is done, at least not much. What's happening is the yeast are cleaning up after themselves, absorbing and metabolizing some of the flavors, including off flavors, they threw earlier when times were really good. So if you let the yeast finish, then rack the beer off the sediment, you'll get a clearer beer but as mentioned, balance that against the chance of introducing air into the beer.

 

i've never done a tertiary, but I typically rack to a secondary for my 5 gallon batches, especially if i'm dry-hopping, adding wood, or there was a lot of sludge in the kettle (like chocolate for a porter).
for the smaller test batches, i only do the primary. and truth be told, i usually don't bother with an autosiphon when bottling those batches, i just ask the wife to help me pour it in. i'm still careful not to splash too much, but i don't worry as much.
and when you're pouring the beer into a glass, you can still be careful to leave the lat 1/4 inch or so in case there's any sediment in there