Agree with Tombeau, if you're signalling you should be decelerating anyway so let the throttle roll off.
Unless of course you are actually overtaking something
I did manage to overtake a Morris Z delivery van (based on a morris8) the other day
Used hand signals to take my test back in early eighties, can't remember if statutory then or because my TS250 didn't have indicators.
I'm very comfortable with it, change down at the same time, no worries, but do keep an eagle eye out for potholes, they can ruin your day!
Don't think I ever owned a bike in UK with indicators, though they would of been handy on the Ratbike GS750 below, quite different to my current bike
converted from track use it had a Yoshimura 900 race kit, big bore Mikunis K&N's etc. & went like stink, left everthing standing from the lights & shot really cool flames on the overrun, the most fun bike I've ever had on two wheels.
Strengthened headstock no visible frame number, sold it to a policeman
Hand signals with clipons is problematic, but I was usually travelling at several warp factors higher than anything else on the road, so seldom bothered.
Only time I've relied on indicators is in Taiwan (18yrs there) where no one else bothers to indicate or even drive on the right side of the road for that matter.
Pavement ok too in a pinch, traffic lights optional!
You hang on for dear life, brain on high alert whilst driving in what could pass for a computer crash & burn driving game, except of course the stakes are a little higher.
Only time hands come off bars out there is when you prise them off at end of journey & reach for the valium!