a booster strap will give you more power, I know some old gs guys would put a shim behind the calf for racing. You could use foam or a shin gaurd. as far as adding a buckle I dont think the agent has the space for it, plus it should have 2 up high and 1 across the fore foot. The liner is thick in that boot. try the reach around method on your boots untill the liner gives in. I have an old pair of scarpa avants and are using them on my shoots with dukes. I have to CRANK the buckles tight so they drive the ski.
the reach around method.
after you get your boots on and are in the boot first lock the walk mode in the furthest forward setting you can making sure not to lean agains the highback so you know it is all the way forward, then pull back on the highback till it clicks into place.
tighten your boots normally, then drop to the right knee leaving the left foot in front of you. open the 2nd buckle and go 1 bar forward. intead of trying to lach it with the left hand, reach behind your left leg with your right hand and use it to lach the buckle. do the same with the #1 buckle and re tighten your power strap. do the same with the other boot and befor you click in. stand up, open the buckle over your fore foot and move it 1 bar forward, use your pole to lock it down or step on it with your other foot.
I am sorry if it reads shitty on line but it will work, pm me your # and we can talk. It still sounds like a forward lean issue but i hope this helps