Well, just depends on what you're focus at the moment.
paraparaMAX is a marathon, if you wanna train your consistency, the fact of not choking everywhere, yes, playing this beatmap is a good thing.
Otherwise, if you want to play 3* with ease, I think the best is just to play a lot of different beatmaps. Some of them are mostly little jumps, others are triple taps, others are focus about stamina and speed... If you wanna do it with ease, the best way is being able to do everything. A single beatmap, whatever its length, and whatever how many times you played it, won't teach you that.