Normally VMware would recommend either Fixed or MRU depending on the testing in the compatibility guide. Its upto the storage vendor to recommend if round Robin is supported for the array. What I would personally recommend is compare the performance of VMs on Round Robin based datastore and Fixed pathing based datastore. Select the one which works better for your environment.
In most of the cases, Roundrobin is better if supported for your array. You can change the Multipathing during normal working hours, but there would be a loss of live IOs during the change duration for VMs. So we recommend it to be done during non-business hours.
In regards to IOPS, VMware recommend IOPS to 1000 for Roundrobin, unless the storage vendor recommends a specific value which is 3 here. Check with vendor if they recommend this value. The reason why IOPS needs to be mentioned for Roundrobin is since the path changes once the IOPS value hits 1000 and the IO moves to the new path.
Please mark my answer as helpful or correct if it guided you!!!