An R2 device may validly be in Write Disabled or Not Ready state when replication is active. You choose. So technically you can read from an R2, but as data changes from the R1 side, the changes will not be known and understood by the file system that the R2 is mounted on. It's not like NAS. So while it sounds good to read from the R2, in practice there are not many use cases (while replicating).
If you stop replication (split will make the R2 R/W), then you loos your DR position. Better to SNAP or Clone the R2 device and mount the local replica, depending on what you are trying to achieve.
What is your goal here?