I know for big pieces you can do them section by section but could you for instance line the entire piece first, and then fill the rest in over the course of a few days? What would be the opening to get it done and what would be too long?
I wouldn't say its impossible... However you dont want to overwork the skin too much.
It happens in conventions all the time and I dont really think it makes a negative visual effect on the tattoo, but maybe more discomfort for the client? I had someone come to fill some parts of this design in solid black. I managed to get half the lines and black done, however the next day, they came back and I wouldn't dare go over the black again. The lines weren't so bad to go up to but he did say it was mildly uncomfortable (I guess in perspective, thats nothing haha)
I think it solely depends on what it is? (Sorry for the long post, only just saw after writing it all lol)
if you're hardcore go for it, but not suggested. If you do it, try to cover a section once it is finished for an hour and promote healing immediately with aquaphor. More great tattoo aftercare tips are ideal for this kind of undertaking, but we've got some BA dudes that get their tattoo all day, and rotate back to an old section after a time, so it's possible, just not for everyone.