Brushing new plaster frequently helps keep the plaster smooth. If you fail to brush it is possible for rough spots to develop. Smooth plaster is obviously very nice to have, but even in the worst case, no brushing, the result isn't horrible. If you brush once a day for a few days it will probably be just fine.
The other important thing is to keep an eye on the PH and never let the PH get too high. High PH can result in scaling, which can ruin the appearance, depending on the finish, and can be a lot rougher than failing to brush can be. Usually testing and adjusting once a day is enough, sometimes PH requires adjusting twice a day for the first few weeks.
The other important thing is to keep an eye on the PH and never let the PH get too high. High PH can result in scaling, which can ruin the appearance, depending on the finish, and can be a lot rougher than failing to brush can be. Usually testing and adjusting once a day is enough, sometimes PH requires adjusting twice a day for the first few weeks.