R.lineatus is a gorgeous species grown for its finely textured palmate foliage – fresh green above, silver beneath. It forms a suckering colony and can travel quite widely but I’ve never seen it become a real nuisance like some Rubus.
I’d grow it among other shrubs and robust herbaceous perennials and let it wander about. The contrast with broad leathery leaves is very telling. As the foliage is damaged by drought and freezing winds it needs moist sheltered woodland to look its best.
Vietnamensis is very like the species but Barry Clark (holder of the national Rubus collection) reckoned it might be a little hardier