It intrigues me a little why ppl want to up the revs.
I suppose every now & again when you come across an overgrown lawn it helps to have that extra power but if thats happening too often, time to get a more powerful mower.
Its kinda like getting a kwaka 750 & boring it out to 810, why not get the 900 in the first place ?
Honda obviously realise that more power can be extracted but consider that the factory setting to be the right compromise for the masses, a balance between power, reliability & longevity.
My view is that if its not a lawn, don't mow it with a lawn mower.
Don't mean to sound condescending, sometimes I abuse my gear too.
Just an after thought, suppose if you up the revs, its just another option.
Its your decision if you want to run it flat out or not.