Hawthorn is closely related to pear, and is often used as a scion for it. If it behaves like pear, its very good bow wood. But the knots...backed with sinew it should be great.
FYI, pear has very similar properties as yew. Juvenile wood (branches, saplings) is even more flexible.
My fastest self bow at 10gpp so far was a straight hawthorn sapling, toasted belly: 53.5", 33# at 27", 216 g weight, 0.5 cm visible set after shooting. shot 175-178 fps at 10gpp, just over 200 m distance. I broke it when testing its speed at 28"... at a pin on the back.