Of course your climbing movement and technique will be improved by a steady diet of gym climbing!
If you want to climb harder then go to the gym and boulder on plastic a lot- several days per week, and you will make improvements in power and strength, no doubt, but also in technique and movement kinesthetics, so long as you are paying attention to how the kids climb, and incorporate better and better movement into your own bag of tricks. Take that improved power and bouldering technique outdoors and waste it where you will- your hard projects will be easier for you without question.