I'm fairly well versed in using a decomp for starting stuff. I have a rather recalcitrant pre war BSA that is impossible to get over tdc as the single spring clutch will slip. I'm also building a high comp velocette at the moment so that'll be a drill to learn too. It's all part of the fun.It's worth doing as you say, it's a more graceful way to stop the engine. Also, once you've got the technique sorted, I think it is a nicer way to start the bike as well by using the valve lifter with a long sweeping kick (I think those are the two words I was told for the kick).