Considering the tech didn't know a helicoil I think I would get second opinion on saving the head without removal. Take it back to place that did original fix.

p.s. A closing post to your prior topic and 2 way links to/from this one would provide continuity and help members browsing topics or doing a search.

98 Mystique LS v6 atx 110,000km
97 Contour LX v6 atx 125,000km
stock CD on LS, cass on LX
spoiler, tinted windows on LS only
4 wheel discs on LX only
All other available options on both