There's not much sense in adding more acid than is necessary, especially if you're using a non-volatile acid.
Considering boiling with acid is part of several extraction methods, evaporating on a hot water bath is nothing to worry about. Increasing airflow would hasten evaporation - using an inert gas would lessen the possibility of oxidation.
Don't go too high on the acid concentration, there are practical reasons for keeping the volume of polar phase within a certain proportion of the non-polar phase.
Most DMT salts are exceedingly soluble in water.
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli