Commenting on Cassie’s video comparing SL mesh bodies, and her note that Bakes on Mesh doesn’t seem to improve performance, Patchouli W provides this analysis:

BoM’s true value contribution will only surface once onion-skin geometry is stripped away from BoM-optimized versions of the same body and people stop wearing more than one copy of the body geometry because of the removal of said onion-skins. The other optimization that will need to happen – and this is trickier because of limitations on how BoM works currently as well as so many legacy mesh clothing items being reliant on them – is the removal of legacy alpha cutting in favor of a BoM model that can handle ‘cuts’ made by using system layer alphas – this would reduce the amount of duplicated geometry required to fake smooth transitions between disparate pieces of geometry as well.

Only when these two changes are pushed through in full will the full value of BoM in cutting the impact of mesh bodies on the SL grid be fully realized. Then there’s the issue of trying to port this work over to cope with normal and specular/env channels baking, which is an entirely new kettle of fish since the way normals are blended is a little different compared to diffuse and specular texture layering.

This may be true or not true, but what’s striking to me is all the 3D graphics technical jargon one must know to understand the state of Second Life mesh. Or as it was expressed in the immortal line from The Limey: “There’s one thing I don’t understand. The thing I don’t understand is every motherf#@&ing word you’re saying.”