Asymmetric thrust or a single engine failure at low speed in a V/STOL aircraft needing significant jet-borne lift is something which has always pretty well ruled out the twin engined V/STOL concept......
Back in the 1950s, some brave souls flew this twin-Nene deflected-jet Meteor IV research aircraft down to about 70KIAS - without a bang seat. I hate to imagine what would have happened if one engine had failed at such low speeds on the approach...it would have rolled inverted in about half a heart beat. So presumably the tests were conducted at a sufficient altitude for the hapless pilot, in the event of an engine or duct failure, to throttle back the other engine, recover the thing to a gliding attitude and then decide whether to attempt a force landing or to hit the silk....