Because of the way you patched, you're making it difficult to find all the SMD0 references...
Because you also have an SMD0 at root scope, that code is now accessing the one at root instead of the one in H_EC.
I would start by changing SMD0 in root scope to XMD0, then all SMD0 that refer to the root scope so they refer to XMD0 (compiler will find them for you).
That way when you change SMD0 in H_EC scope to SMDP (later), the compiler will find all the places you need to patch for you...
(hint: there are only those two you mention).
Also... If you understand ACPI well enough, you can also just analyze the location of each SMD0 reference to decide whether it is accessing the H_EC SMD0 or root scope SMD0.
First example is a write... Would be translated to WECB(0x1c,256,FB4).
Second example is a read... Would be translated to Store(RECB(0x1c,256),FB4)
There are plenty of SMD0 examples in the various battery patches in my laptop repo...