I'd much rather have the thickness and the ability to machine later on.  10 hp is too easy to get from other ways.  That's an air filter base change, or a carb spacer change, or an A/F ratio change.

Depends on the horsepower per cubic inch, but a .030 over 428 block with a 4.25 stroker crank will be right at 462.  At .060 over just under 469 so we'll just call it a 7 cubic inch difference.  Assuming we have a build that produces 1.5 ponies per cube (2019 Blair Patrick FE build anyone?) naturally aspirated, 10.5 additional horsepower.  This is a super simplified comparison, but it gives a basic idea.

I think that block could easily go .060" over - Jay

Well, my client is one that liked the sound of the engine in 4th gear....at 100mph. Honestly I can't tell what gave out first. Pushrods were tangled up in the rotating assembly and lifters were in pieces everywhere. The car and engine only had 12k miles, and was built by Shelby American. I'm sure he'll take better care this time. We're getting close to $30k in parts....

Not sure how he gets nearly 11.5:1 compression calculation.

Using Diamond's calculator (decent third party data) I get 10.86:1 with .010 deck clearance, a Fel-Pro 1020 gasket and assuming a .010 cut below nominal spec on the deck.
Above also assumes a .250 crevice volume, and the Mahle specified 7cc dome volume.