"I don't understand the code anymore. It works." That's fine... today.

"I will never need to understand the code again" is a much different statement.

If you don't understand the code, and the code wasn't written by any human, when you're eventually painted into a corner, how hard is it going to be to get out? Will it be easier or harder than maintaining an understanding through however long it takes to get to that point?

You may be betting your company on the answer. How sure are you?