I've come across this mindset before - I'm doing SAR so I can break the rules. Taking off over gross weight is BREAKING THE RULES.
The maintenance schedule is based on the aircraft operating within it's certification (release) requirements. Do it another way and you prejudice the integrity of your machine. Parts are 'lifed' based on the stresses and strains predicted when you do it by the book.
If you can't do your mission with the fuel weight available then turn the mission down! That may get someone's attention and maybe they will decide that you need something bigger and better. Keep on doing the job and as sure as eggs are eggs your protests will fall on deaf ears.
Just remember that when you get back in one piece having used and abused your trusty steed that some other poor sod has to take it on an equally demanding mission.
G
