Bled and changed fluid in brake and clutch systems. Followed Sirby's procedure for AE clutch bleeding, namely switch ignition on and off while cracking bleed nipple open/closed and topping up master cylinder (sure empties quick!). Seems to work well thanks for the tip.
Old fluid in clutch pretty grimy looking but the bubbles I think were entering around my crummy plastic tubing or the nipple threads.
Only issues previously were loud CLUNK/JOLT when shifting into first from a standstill, hot or cold, and the occasional clutch momentary re-engagement when rolling to a stop. No change with either since bleeding so guess that wasn't the cause.
One thing Sirby didn't mention. On ignition switch on after bleeding, a fault code came up and bike wouldn't start. SH_ _ 25 I think, error in YCC-S system. So on next switch on I quickly pressed start button and she fired up and no fault code has shown since. There was some repeated clatter and hesitancy from the clutch for the first couple of starts, but not since.