Just my own experience.....
When I took my BF 225 in for the second maintenance run, the dealer told me I was babying the motor too much, His HDS showed that I only had it up to WOT (6000 rpm) once, briefly in that first 100 hours. His advice was to run it at WOT whenever I got the chance, which I did. The engine is now 17 years old with 2300+ hours and still runs great. So, take that for what it's worth. I hope there are other opinions that folks will share.
And BTW - The key to keeping any outboard in top notch condition is to run them often and be a stickler on maintenance.