I found an interesting paper on establishing it.
The only apparent limitation is that establishment of kura clover is more challenging than other forage legumes. The reason for this is that the pattern of development of kura clover seedlings is different from other legumes. Kura clover seedlings germinate, emerge and develop the first three true leaves at about the same rate as other legumes, but then leaf development slows and energy from photosynthesis is used for root and rhizome development. Also, kura clover produces few or no upright stems during the first year and its short stature makes it extremely susceptible to shading from weeds or existing grass in the field.
It sounds like a decent choice to plant on top of a zone>2 tree stump.
Evidence exists that strains of Rhizobia specific for kura clover are not as robust as other Rhizobia and do not survive long after application to the seed. Therefore it is recommended to apply Rhizobia to the seed on the day of sowing.