To add to the good comments already made;
Set up-
'Just tight, but not taught', if you hold the sail near the batten pocket end and push the batten tip inwards gently the webbing retainers should initially remain tight, until you push harder. I do not adjust them for different winds.
Overly tight battens will be harder to flick through in manouvers. They may also hook the leach hindering the generation of good inverse flow when sailing by the lee downwind. If in doubt then you are likely best slackening them off, but not so slack that they may fall out of the webbing retainers.
Kicker/Vang-
With good technique in tacks and gybes a little kicker alone should be enough to flick them every time. This is more a case of just taking the slack out of it so the boom is braced and unable to ride up in manoeuvres, rather than applying any real tension - as you do want that eased in very light winds too.
Technique-
The battens not flicking is a good indicator of needing some better technique on manoeuvres;
Tacks-
a good roll tack involves pulling the boat upright in time with sheeting the sail in. The moment of bouncing your weight down on the new side should be enough to flick the battens (provided the kicker is not very loose).
Wind in the sail will help - having turned through enough angle and the force of sheeting in.
Gybes-
On all gybes you should be grabbing the mainsheet falls from the boom, either all 4 or just the rear two in order to give you a 1:1 pull. This is important to pull the boom across promptly as you pass dead downwind in medium or strong breeze. It is also important in light breeze so that you can give the sail a 1:1 pull to flick the battens as you exit the gybe. With the kicker overly loose the boom will rise and the leach open, then that flick force will not reach the battens at the top of the sail and they might not flick through.
Downhaul-
Tighter downhaul helps the battens flick, as they then have less tension and depth. However, you want your downhaul/cunningham slack in light winds. Pullining the downhaul on before a manouver and releasing it after is one option. Alternatively, if the battens fail to flick you can pull it to fick a backed batten, provided there is a little wind in the sail. By pulling the downhaul upwards and releasing again from the deck in front of the cleat enables it to be instantaneously released again. Pulling the downhaul should never be necessary with a small amount of vang tension and good tecnique, but it is an option available after a bad tack or gybe
Design-
This is not an issue limited to the RS Aero, it is an issue relating to all sails with full length battens.
A 'soft' sail (no full length battens like a Laser) is different to a 'semi soft' sail (some full length battens like an RS Aero) and they are different again to a 'hard' sail with full length battens throughout
The semi soft design of the RS Aero has the benefit of giving us an efficient square top shape whist also retaining the ability to lose power easily when eased.
However it does then require some practice on good tack & gybe technique to have them pop reliably each time, but that is a very similar technique to a good tack or gybe with a soft sail anyway...