Just to address those...
These days the Pond aluminum block is $5600 and up. Shelby is about $1000 higher.
BBM iron block is around $3500 I think.
Absolutely no issue whatsoever with running aluminum heads on cast iron blocks. Zero. There are actually more chances of leaks with the all-aluminum FE engines than the cast iron/aluminum pieces. Plus, I recommend that all my all-aluminum customers run Moroso Ceramic Seal through the tank on an initial install. Don't have to do that on a "hybrid" engine.
A lot of your OEM combinations are all-aluminum. However, they have OEM quantity, OEM manufacturing, and OEM foundries behind them. Big difference.
Personally, knowing all that I know, I wouldn't consider an aluminum block a bragging right, but I could see where it could be taken that way. Same way as bragging about having a "6-speed".
By the way, RK, this post wasn't an argument to your points, but just trying to clarify some things out there that could be really considered rumors, as you call them.