Blackberry/raspberry polyculture

Does anybody have any specific information on pollinator plants that flower at the same time when brambles bloom. If anyone has experience with carpeting/groundcover plants that thrive under the canopy of bramble thickets wild or cultivated. Currently expirimenting with strawberries planted in with blackberries after witnessing this companionship in the wild.
Preference towards native plants
Located in sw michigan

Deadnettle and Creeping Charlie might be good. They bloom about the same time and my bees love them.

Strawberries under blackberries is a great combo, I've seen that work well in the wild too. White clover is worth trying as a living mulch between the rows, it fixes nitrogen and the bees love it when it flowers alongside the brambles. Comfrey is another good one if you've got the space, deep roots pull up nutrients and the leaves make decent mulch when you chop them.