UPDATE:
I got the script working. It finally stopped crashing. Not sharing it yet as I’ve not figured out how to use it for the entire skeleton yet, just parts. But the hardest part is done. It works for any skeletal mesh/bones. It’s not Metahuman specific by nature of the script, but of course its compatible. 
Give it a list of Skeletal Meshes and Bones; then watch it delete every bone matching the given names on every skeletal mesh given. In regards to using it on the LOD 0 Metahuman, I have only figured out what bones you can “freely” delete in the fingers of each hand (minus the thumb). I started in this area because it proved the be the most unforgiving when deleting bones. Thanks to my relentless testing, no skin weight modification needed to take place, whatsoever! 
I settled on what I believe to be a best-case scenario for trimming down LOD 0 to maintain 90% of its perceived deform fidelity whilst reducing the raw bone count by ~60%. The secret is in the order in which you delete the bones.
The order of operation for bone deletion took a considerable amount of time to decipher because the surrounding bones soak up the skin weights from the newly deleted bone. One mistake and the finger is going to bend like paper or a rubix cube. Hard lines, not pretty enough for LOD 0. Many permutations were manually attempted.
I eventually found a reasonable compromise (between deleting as much as possible and leaving LOD 0 fidelity intact) which involved deleting 8 bones from each finger, leaving the 3 “bulge” bones & the “palmMid” bone on each finger. This reduces each finger from 22 bones to 8 @ LOD 0 and the fingers still looks mighty beautiful with so less corrective bones involved. A worthy compromise in my eyes. LOD 1+ is of no concern due to their weighted bones containing nearly no correctives. Any any correctives involved I plan to target in my LOD 0 hit list. Here is a picture of the hand flexing @ LOD 0 after losing 60% of its bones. The hard part was making the squishy parts on the inside of each finger stay intact at many degrees of flexion & extension.
Very nice! Hopefully it actually helps performance. 
My animations are all running just fine, but I imagine they might need re targeting? We will see…
Tomorrow I’ll start knocking out the thumb solution and start moving up the arms. The feet should be easier than the hands. I plan to make them crude with simply toe flexing, nothing fancy like the hands.