I had my done on the F115 at 700 hours earlier this spring. A few thousandths out of spec. If I can find the readings I'll post them. I wanted to see how much the wear was over time. It wasn't much. Not affecting the engine performance anyways.
I was going to do it myself but had purchased another boat. Working on two engines wasn't feasable at the time. Could have gone another 700 + hours probably without any problems.
That said, I don't think you need to do it, at least at 700 hours. On the other hand, Its not very difficult to do and I don't think you need to worry so much about breaking anything if your careful. We would often adjust the rockers on large 4 stroke diesels. Even easier. The adjustment is made with screwdriver and feeler gage (no pads).