these are just my thoughts,, and many ways to approach your 28 inch goal,,,
in my experience ,, 57 nock to nock,, would be pushing it for a 28 inch draw,, yes it has been done,, and more,,
but you increase the odds of your bow failing,,
if you are in love with the handle,, I would rawhide back it,, or put a thin layer of sinew,, thats just me,,
if you reduce the handle slightly so the whole bow works,,, your odds of success will increase with more working wood,,
Keep in mind, that the guys that say it will work with stiff handle at the 28 inch draw,, are guys with exceptional skill in tillering,,and intuition about bows from making millions of bows,, that may be U i don't know your skill level,,
that being said,, I would not try it,, I would shorten the draw,,or bend the handle,, back it or all of the above,, I am a chicken sometimes,,