issues solved!
shortened and braided motor wires, lowered punch to 20%, set timing to 15, went back to firmware 2.42 (i think...the least non-beta one anyway) and it's all good..think the wire shortening did the most difference though.
it's brilliant now, even on a crappy half flat 4s i got zero cogging
E-revo 3.3 conversion, 249kv outrunner, 6s, MMM
the porthole from the noob world an here has been opened!! that's how i got in.