Don't confuse the different MGB designs, folks. The S61 is terrifically vulnerable to loss of lube on its sleeve bearing inputs (sleeve bearings are like the crankshaft journal bearings, where metal slides on metal, vice roller or ball bearings, where the two surfaces essentially roll against each other). For an S61, the loss of oil pressure for more that a minute or two can lead to melting of the inputs and cutting of both engine inputs - a total power loss. The "aux lube" for an S61 is a secondary pressure system for these sleeves to cool and lube them, and prevent dual engine cut in a few minutes.
The S92 has dual independant MGB pumps, each able to sustain acceptable pressure, and has loss of lube protection via the external isolation valve, as well as a quantity sensor and warning system. The transmission was reported to run more than 3 hours during its loss of lube tests. There are no sleeve bearings or such that are vulnerable to the loss of pressure, like the S61.
Yes, they did learn something since the S61, I guess.