And what is for heavy / bittube2 algo?

Also, did someone test fragments and bralock, if I understand correctly fragments is more important parameter to tune?

Interested in settings for bittube2 algo for RX 570 4GB, Vega 56, Vega 64

"fragments" : 0,1,2,4,8,16,32,64 or 128. It can boost your hashrate if you find the right value for your GPU
"bralock": 1-256, parameter to tune, it *may* add some extra hash, it can differ between algos