||A fair amount of material could be removed without affecting strength, but the cost to do it is too high on a $/lb basis to make it worth considering. These are already going to be expensive and I don't want to add any more to that at this point.
The bedplate material is 1045 steel. I'm not concerned about galvanic corrosion, there are many other metals other than cast iron in contact with the block at any given time (zinc plated fasteners, aluminum, steel). I considered 7075 aluminum, but too many people get weirded out with some possible pitfalls of dissimilar metals - so from a marketing standpoint, 7075 is just too hard to sell.
I was surprised at the variation in this block's original machining for the stock girdle. This could be an anomaly though as this particular block did suffer a good dose of overheating before it became a boat anchor. Regardless, the bedplate has extra material planned into it to allow for fitting it to any block even if there is some variation.