It wont be a problem to take clones from it, dont stress out about a bit of leaf burn it's not a problem, it's just a sign you need to back off the nutes. I'd just wait a few days to be sure its growing vigorously and go for it. When cloning I always pull all the fan leaf except the top set anyways pretty much.
Also remember that while a leaf may look ugly to you it's doing a job and how it looks to you may not be how the plant feels about it, it's your job to learn what the plant is doing with the leaf. Much worse than a bit of burn is twisting and deformity.
Rule of thumb is if its growing and not stunted it's not a problem
