Thanks everyone for the advice,
I think I get it now. Running around hand held shooting action sequences is definitely a no no with BMCC 2.5K (or any rolling shutter camera) unless going for a ruined shot.
No known plans on improve rolling shutter on BMCC 2.5K

For quick pans (on a tripod), or I guess any movement in one direction, rolling shutter can be corrected in post.
BMCC4K looks more tempting for me at this moment, along as BMD will be them shipping from July as stated!
Thanks,
Jules