Lastly i should add I had to get serious about thread repairs dealing with air cooled 4 stroke engines. They get so damn hot the alloy goes soft (annealing?) after not too many heat cycles and it causes hell. the XR400 was known for blowing head gaskets, what happened was the studs pulled out of the barrel. The initial fix was 1D helicoils. They pulled out too. So now you have a big hole. Enter the loc-sert.
Eventually we went to 2D and 3D inserts in helicoils but the thread jumping issue was such a pain if the installer was not super careful.
2D and 3D timeserts was the real answer, i’ve never had one pull out if it didn’t have a helicoil installed first.
So my simple rule is this.
If it’s an assemble and forget fastener (crankcase bolts) the helicoil is fine.
A high use fastner (drain plug) the Time Sert is the go.