As you've mentioned, reducing a boost to 10psi will greatly increases turbo life. Turbo life expectancy is at about 60K with normal driving.
Rebuilt streetported with 3" exhaust...you'll love the sound. 'Cuz I do. hehe...
Hope you're not driving long distance, for the sake of gas mileage you are about to get.
My opinion is life expectancy of a rotary is how it is maintained and treated. If you abuse it you'll deserve the consequences. Just a plain common sense
BTW, good find, man.