The HF tool's hooks are too fat to fit between a pair of Koni spring coils. I guess if you never intend to compress car coils, you could grind them small enough.
I don't remember reading that the BMW stock shocks are made to be rebuilt, though if you could find new springs you could replace them anyway.
I ended up using a crazy combination of a bottle cap installer and something slipped between an upper pair of coils, I think a previous incarnation of my stupid bag mounts. It worked surprisingly easy. The bottle capper stood kind of like a little drill press, but the handle pressed the capper part down rather than a drill. I just had the silly thing sitting around in my shop, I don't even use it for bottling beer.