The only way to remove scratches from glass that has to stand up to heat is to polish them out using successively finer grades of polishing compounds. Simply do a web search for 'glass scratch removal' and you will find lots of info and kits. I found on one search page three kits under $35 each.

HomeSealed, Cerium Oxide is widely used for grinding and polishing glass and since it does fall into the rare earth category, it is very possible (likely) that you are using it as a buffing compound. The very finest grade of cerium is reserved for applications such as grinding and polishing high end telescope lenses and it is eye-openingly expensive.

There are a number of ways to remove scratches from glass and almost all of them do it by grinding the glass surface, removing material, and causing a "distortion lens" to form in the glass surface. I have had the opportunity to test and/or use a number of different systems for scratch removal, and the best in my opinion is G-Force by GlasWeld. https://www.google.com/search?q=g+force+scratch+removal+system&rlz=1C1CHBF_enUS879US879&oq=g+force+scratch&aqs=chrome.0.0j69i57j0l3j69i64.6522j0j7&sourceid=chrome&ie=UTF-8#kpvalbx=_YtYYXtHCAoy6tQaziqeYDw20 When used correctly this system will remove scratches without removing glass and won't cause distortion. When complete, even with a very close inspection, you won't be able to tell that the glass was ever scratched in the first place. I would recommend that you call GlasWeld directly to find out if there is someone in your area who removes scratches using this system and start there. By disclaimer I am in no way affiliated with GlasWeld nor any other company dealing with scratch removal from glass.

If you need to stand on your head at a 45 degree angle between the hours of 2-3pm, and use a magnifying glass just to see the imperfection, it won't likely get replaced. I'm being facetious of course, but I'd had some requests not all that far off from that over the years. Not that facetious. I have had some as well that weren't far off from that. In fact I once had to deal with both doors/lites of five year old laminated patio door. (Note once again FIVE year old patio doors) The homeowners originally complained to the window company because when they (homeowners) laid on the floor at night in the dark with the doors roughly half-way open and the the porch lights on, the homeowners could see distortion in the laminated glass from certain angles. In all other conditions the glass in the doors was pristine. The window company APPROVED the reject and after that I was asked for my professional opinion. As i recall my first reaction was something to the effect of "are you #$%$%@ kidding me? Per scratches in glass, it's all about viewing criteria, as noted in the two previous posts.