[Development] MouseEvent 'caps' confusion (5.3)

[Rick Stockton]

I'm trying to add a field of flags for Qt::MouseEvent, and I've been
advised that stealing 8 (or 16 ???) unused bits from the new 'caps'
field is the best way to go. (Yeah, I see why an 'unused' bit
Qt::MouseButtons would be really bad.) But I am confused about a few things:

Why is set of new protected functions (reading and writing portions of
'caps') defined in QGuiApplicationPrivate, rather than a new class
"QMouseEventPrivate" within QEvent? (Would the corresponding d-> change
the size of the Class?)

Is QGuiApplication already accessible from classes and modules which
might want to be involved in these flags?

Should I take all 16 high order bits (providing 15 flags), or take just
one byte - 0x00FF0000 ?

I now that that these questions are more suitable as IRC material, but
my hours are incompatible with the EU workday. Sorry.