Too many years ago to remember all the details but when I needed all mine replaced, I got the best high temp bolts I could find in the US, and the recommended upgraded exhaust gasket, and carried them with me down to Mexico. Lubed each bolt according to the recommendations of many mechanics, loaned my torque wrench set properly to the mechanic and let them have at it. The next year, had them re-tightened to specs but didn't re-oil them. ~10 years later they were still good. Costs for all they did, including removing 3 broken studs, was under $100.
From my reading, I thought that I was supposed to check the torque once a year but I was a bit lazy on that point. And the bolts are supposed to be changed regularly if I recall correctly, along with the gasket. Sort of a temp related thing though. If you do a lot of summer travel (I'm a snow bird so not often driving in over 80 F temps), then an aggressive maintenance procedure is called for. If you're a snow bird too, then you can probably do a moderate or minimum procedure. Especially if you're in the 3K to 5K miles or less per year group.
JMO mostly and you know what opinions are worth.