Often, a certain limit exists only because there doesn't feel like a sensible need to go higher, so VMware never tested as such.
Sometimes, these limits are hardcoded in the interests of sanity, sometimes, it's just a case that exceeding them puts you into "unsupported" territory.
Let's say I had 60 hosts. I would suggest at least two, maybe more clusters should be made. I don't want to end up with 600+ LUNs presented to 60 hosts, it's more manageable to have 200 on each cluster. If you have 60 hosts, there are good odds that you've reached this number of LUNs.
Remember that I can manage many clusters per datacenter.
If you feel 32 hosts in a cluster is a bottleneck I'm sure you're doing something wrong.