It is a lot easier to handle strips than single frames. Unless you are using sheet film, I can't see a good reason for single frames. Typically one would keep 35mm in groups of 6, 120 in anything from 1 (6x12), 2 (6x9), 3 (6x7,6x6) and 4 (6x4.5). If I have less than a set I include some unexposed film to make the strip as long as possible. The lengths are really dictated by the size of a filing sheet, and the ease of contact printing a single film on something around 8x10" paper.
A single frame is easier to drop, harder to handle without getting finger prints on the film, and much harder to align in the negative carrier.
I would not keep roll film in one uncut roll either. That is guaranteed to cause scratches and the roll is hard to control.
If you already have single frames, that's what you have. But I would consider using strips in the future.
-Graham