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By individually adjusting the air screws, while it's running you can determine if all of the idle circuits are clear and working something close to correct. You probably need to go back to a bench sync start point though to make sure you are looking at the idle circuit in isolation.I'd not sync them with a gauge until you understand if the idle circuits are functioning else you risk compensating for impaired idle circuit by raising a throttle slide, which is back to front logic wise.
I think you can leave them set as Bryan explains, certainly won't be anything much away from ideal depending on how diligent they are set initially. I think the whole carb sync thing with gauges has been misaligned over the years as something that is part of tuning the engine. I can't construct any competent case for altering the carb's slides away from mechanical parity to run the engine correctly under load.
Honda provide in their manuals the method for adjusting the air/idle screws at tickover to produce an even running engine. This is the correct device for equalising the cylinders at very very low engine speeds as they are effectively micrometer adjustment throttles for each cylinder..... Not the main throttle slides.
As Bryan has posted over the years on here, you need all the setup done, verified and complete before you put any gauges near them.The gauges in my view are just a device for a workshop to get the carb's slides something close to parity without having to dismantle the bike. That assumes all other things are working correctly else it'll more likely put an error on the bike. Bench setting should hold sway if done properly, the confidence should go with that as an engineering principle, not the other way round.