The rules I am "using" (I ever used just a part of them and am currently expanding them) actually delete skills rather than adding more (no style skill, no modifications of the core rules, the disarm, feint, locking holds, tackling, reverse stroke and a bunch of other skills are deleted...) so at the next level you just have to redistribute the freed DPs.
I've been working on them casually for one year and a half now. They are approaching the state where they can be playtested. The whole thing is meant to use the RM core rules, allow more possibilities (for example an axe can shatter a shield, a dagger ignores armour in the critical descriptions and a polearm may be used to unseat a horseman), raise DB and make hits more devastating. You hit less but when you do it hurts more.
It takes a long time because balancing the whole thing for melee, hand to hand, and foot vs foot, foot vs mounted or mounted vs mounted is a mind better. I just hope playtesting won't send me back to the start :p