The lessons in PLL are VERY short, so I would think you could do a whole lesson. I'm not sure if you are referring to a specific lesson in there, but PLL is very short for each lesson. For some lessons that are fill-in-the-blank, I do allow our DC to just write the answer beside the corresponding number.
We mostly though do PLL orally, probably 75% of the time. We also skip some of the lessons like picture study (we do those with other materials) and a lot of the dictation (again done in other ways).
I'm not sure this helps, but I think sloppiness is one thing and writing neatly another. Some children just don't have the fine motor strength to write as neatly as others. I have 2 with sensory needs and handwriting is very hard for them.
I would expect their best, but I try to stay away from the word "perfect". Hope this helps.