Sure thing! Edited in my post.
Does that solve the problem, @zig
I mean, anyways it doesn't make sense to put the osc messages in props. You can delete target, address, preArgs in the matrix props. Just place target and address inside the fader manualle. Then write the preArgs like this:
[1, @{parent.variables.n}]
and add it to 50 as you like.
OR: Create another variable in the panel called "out". You can use it in the faders preArgs like above using @{parent.variables.out}
Then assign it using the matrix.