I have tried your system and am deeply concerned. I have attached photos.
My process:
1) Hydrator 3.3 > fatliquor 5.0 > hydrator 3.3
2) vachetta pro 1.2 > acidifier 2.0
3) Hydrator 3.3 > fatliquor 5.0 > hydrator 3.3
4) vachetta 2.8
It *barely* softened the leather and the browning is not improved at all. I tried on speedy rolled vachetta handles and side tabs of a cosmetic bag.