I struggled solving my 2 off. For me, there are two types of 2 off: those solved by a specific trick and those purely about correctly routing through. This level is of the 2nd type, and for me more difficult because intuition doesn't help much. It's more about testing alternatives until one works.
Yecch- 2 off still. EDIT I got it yay! Surprising that something like that would come up by accident. EDIT2: I meant that it was annoying to open lock after lock after lock after lock...
