Because you can't use double brackets, you can't do the following:

Specific attribute is not x
AND ((preferred province Y
AND total amount of gifts 1 is >= Z)
OR total amount of gifts 2 is >=Z)2:18:11 PM

so you're forced to set it up as follows:

Specific attribute is not x
(Specific attribute is not x
AND (preferred province Y
AND total amount of gifts 1 is >= Z)
OR total amount of gifts 2 is >=Z)

Where the 2nd line literally doesn't do anything

While it was possible to do it like this here, sometimes specific set ups do not allow for it. The addition of a being allowed to use a double (or more) bracket would allow for better Query Use.