While browsing through header files in experimental I found these sort of things:
sp-object.h
    unsigned int cloned : 1;

    unsigned int set : 1;
    unsigned int value : 1;

sp-namedview.h
    unsigned int editable : 1;
    unsigned int showguides : 1;
    unsigned int showborder : 1;
    unsigned int showpageshadow : 1;

These look very much like a holdover from C which did not have a boolean type like C does.

Is there any viable reason for not simply converting these to boolean?

There are other, similar things that I saw as well (sp-namedview.h):

unsigned int borderlayer : 2;

and I believe this variable is meant to hold an enum type. Should it just be changed to the type of the enum with no alignment or is there a reason to not do that?