I completely agree that this problem is left unclear in the RB and a question to Perry is probably warranted. I am not sure what about A7.55 makes you favor the opinion that you couldn't BFF a CMG, expend a delay MP, and then fire your BMG at the same target (so long as it doesn't leave the hex, violating D3.51). Because of the delay point, the shots are clearly not "simultaneous."
I assume that you are ignoring the parenthesized portion of A7.55 (as cited) since it appears to refer to the target's MPh. However, such rules are often reversed when using Bounding Fire, like the modifiers for "limited view" (Cases J1/J2 become C1/C2) now apply to the firer's MP expenditure, and that a MA must expend an additional MP before taking a second shot rather than waiting for the enemy to expend an extra MP/MF instead.