I didn’t think so but...I definitely didn’t with the rockers removed. Reinstall and see/double check? I don’t risk any damage doing that do I?(if it comes apart)
No, you need the valves closed. You're going in too many directions because the usual suspects have come in and complicated it all to hell and back. The last thing you needed was a leak down tester. That in no way will help you find a DEAD cylinder. You can find it SO much faster with conventional methods. A leak down tester is a tool whose purpose is is to determine the percentage of cylinder leakage. Since you have a dead cylinder and I ASSUME you've gone down every other avenue, such as spark plug, plug wires and the like, your cylinder leak down is 100%.......you don't need a leak down tester to determine THAT.
But you chose who you wanted to listen to, so good luck!