This is what I would like to see available to buy. It adds some of the features found in the later model larger bearing, including a press fit of the bolt to the bearing inner race, and a larger bolt altogether. Basically it is a redesigned bolt and a slightly machined flange seal.
I have found that the inner race of the bearing gets considerably hotter than the outer race. I think that may be why Porsche made the bolt a full-length press fit on the inner race on the larger bearing.
With the head of the bolt being much more massive, it can help dissipate heat from the bearing, or it can be machined for other purposes, like adding a safety bearing.
Being able to add a washer between the bolt head and bearing, perhaps stainless steel, could help prevent push-on separators from popping off.
Making the shank of the bolt as long as possible could help dissipate heat, or a larger heat sink could be bolted on, or a cantilever brace could be installed, or the end of the bolt could be drilled to accept a temperature sensor, like a thermocouple.