I've found both the 3xMIA and FX Aid XL to be incredibly useful in just about every patch. You have Maths already, which can do the 3xMIA tasks if you aren't already using all four Maths channels, so 3xMIA may be more useful if and when you add an additional 104hp. I know some people love O_C, and some of the algorithms look incredibly fun, but I hate menu diving so I can't offer any advice on that one.
I'm not sure that having two filters is a problem. You can use one to self resonate and use that as an extra/sub oscillator, maybe?
What problem are you most hoping to solve? With such a small amount of space left, I would focus on the one thing you really want to do, but can't with your rack as it is.
Have fun and good luck.