Backup - new workflow 4.2

Hello!
I have misunderstood or is it really true that with the new backup workflow on mongo 4.2 is not possible to make a point in time recovery?
The previous backup mode with head database (on filesystem storage) had as a requirement to have a lot of available disk space because a copy of the database was kept and called head database + each snapshot was large in terms of space almost like the head database and each snapshot had to have (on large databases) at least a frequency of 6 hours.
The new backup mode, in terms of space, how has it improved? From what I understand, to take advantage of the “backup to memory” on wiretiger (checkpoint) you still need a lot of space on the db servers. Am I wrong?
Thank you
Mattia