Which Mulberry for understock?

I am trying to decide between morus rubra and morus alba tatarica (red vs white mulberry) as rootstock for a run of Illinois Everbearing trees I have planned. Anyone have experience working with either one? I did a few grafts last year which were successful, but not sure which of the subspecies I used as stock!
Both seem decently hardy for my location, though alba does have an edge being rated a zone lower than rubra.

Either should work . I think Illinois Everbearing is mixed but the leaves look Rubra . Most wild ones are mixed .

white mulberry is considerably longer-lived than red mulberries(100 + years, easily). A good sign of hardiness/tolerance/disease resistance