As Maguras (rim and disc) use mineral oil and most other companies use Dot fluid, then I'd be careful about using any disc brakes other than Magura as Dot oil will kill the seals.
Also remember that the Magura system is a closed one and most disc systems are open, to let heat dissipate - look at the Hope closed system and you'll see they had an adjuster on so you could move the pistons as the fluid heated up.
All that said, you could potentially mate the levers with older (say, 2000/2001) Magura disc calipers such as the Julies, as they used the same hoses and fittings as the HS11/33s.
I've got a bike with Magura drop bar levers fitted to Julie calipers, and it works - so far!
Too many bikes, not enough time!