Did at least some of R Salanter’s students spend a lot of time on mussar rather than gemora? This illustrates a difference between mussar/middos that might precede learning and kabbala that should come later.
Frankly, in our times, nigleh gives us so much new material: interactions w/ colleges, science, psychology, medicine, medinas isroel, etc I can not see getting to nistar until I am 80, bli neder