I am pretty certain that all 5300 v3 support their REST API, so you should be able to get inventory and capacity information.
We do not currently have performance support - last time we looked at the OceanStor REST API, there were not bulk performance API calls available, so we would need to make requests for each volume's statistics, and potentially for each statistic for each volume. Thus, OCI may not be able to retrieve performance data quickly enough to be very useful