I have twice that I remember in 15 plus years. The first time I did it I was a little skeptical but never had an issue as long as I owned the engine (3-4 racing seasons). The second time, well that engine is still roaring the streets on a mini bike.
We have done it many times. Good luck if it's @ the #7 head bolt though -- you'll lose head gaskets there even more than normal.
Stacking heli-coils can be a real chore keeping them in time too, but it's important to do that so that the cylinder is distorted & supported similarly to the other good bolt thread holes.