Calculation of Max LUN Supported in ESX Server

I found my ESX servers could not recover the 65th LUNs that I tried to present to it and myself did log a support call and still pending the reply from VMWare. Beside that, I found another interesting article with the details below.

Article Copy from VMWare

In Multipathing Configurations the Number of Paths Per LUNIs Inconsistent
The hpsa driver in ESX Server might reduce the number of supportable LUNs below the expected maximum limit of 256 when the controller is used in multipath configurations. In multiplath configurations, if all four paths are configured, the total supportable LUNs is reduced to 64. In certain multipath configurations, because each target path consumes an available LUN slot, the total number of supportable LUNs might be reduced to 60.

Workaround
Reduce the number of LUNs on a server until the product of LUNs and paths is less than 256 (LUNs * Number of paths < 256), and if necessary, reduce the LUN count depending on use of multipath until each LUN has the expected number of paths.
The following example shows a configuration with the maximum supportable LUNs presented to an ESX Server installation on four paths, providing all LUNs with the expected number of usable paths:
Path 1: 63 LUNs seen through this path; Total LUN count (63 + 1 path) is less than 256
Path 2: 63 LUNs seen through this path; Total LUN count (63 + 63 + 2 paths) is less than 256
Path 3: 63 LUNs seen through this path; Total LUN count (63 + 63 + 63 + 3 paths) is less than 256
Path 4: 63 LUNs seen through this path; Total LUN count (63 + 63 + 63 + 63 + 4 paths) = 256

If I do use the formula above to calculate my environment, yes, I am at the full limit of 256 LUNs. I have 2 ESX servers which only have 2 HBA connection, and had no problem to present more than 67 physical LUNs to it until now. What I had done now is, I removed 2 HBA connection from each of my ESX servers, and run the rescan, and I found that the LUN is presented as I expected. Again, I am not confirmed with the solution yet and will do another round confirmation with the VMware engineer on this.