If you use the engine cooling circuit for the water side of the charge cooler, then you're using 85degC water to cool the air. Your air to air matrix as standard might not be so efficient, but ambient air is below 20degC most of the time in the UK, so it doesn't need such high efficiency.
To make the charge cooler work for you, you need another radiator and a separate lower temperature cooling circuit. Makes sense in a high boost drag car where you can pack the system with ice for uber-cooling and use a tiny charger cooler, but for your application it adds complexity and weight that is OTT compared to sticking a front mount on there. All in my opinion of course!