The estimated size of the digest file is 0.5% of the logical disk
size in the case of an SHA1 hash and 4K block size—when collision detection is disabled. The estimate is 1.2%
of logical disk size in case of primary and secondary hash—when collision detection is enabled. https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/vmware-view-storage-acce...

CBRC uses a RAM cache to manage the cached disk blocks. The per-VMDK digest file is also loaded into memory.

CBRC should not be enabled under memory-overcommit environments. If a host is memory over-committed and CBRC is enabled – the memory pressure is increased as CBRC also uses memory for the cache. In such cases, the host could experience increased swapping and the overall host performance could be impacted.

Outside reference : https://myvirtualcloud.net/view-storage-accelerator-deep-dive/ may

Should plan according to size of the environment and requirement.