partitons

Only you would be in a position to gauge the level of inconvenience of having two separate drive (partitions), each one only accessible be one respective OS. There are few downsides to using exFAT as a cross-compatible option where the inconvenience of 2 nonadjustable partitions might lead to a "waste" or "lack" of space situation. There is also security to consider, for a select few.

Once clear advantage of exFAT is for cross-compatible data (files that will be used on both systems).

Personally speaking, as drives and drive space are now so relatively cheap, it just comes down to a matter of convenience. But some have a belief (not completely unfounded), that Mac data should be on an encrypted drive using the Mac format, for security as well as journaled reliability, as well having Win-files on an NTFS formatted drive partition.