ZTTO Ultraleichte MS-Kassette MTB 12-Gang 10-50T Micro 10-52T Kettenrad Spline 12s Kassette 10-52T 375g MS Hub M7100 M8100 M9000

In anticipation of a longer distance bikepacking trip, that I just completed, In January I purchased a 10-52T version of the ZTTO Ultralight MS Cassette. I have been running the ZTTO 10-50 version for several years without any problems. I installed the brand new 10-52 cassette on my bikepacker about 3 weeks ago, made adjustments, and believed I was good to go for my ride. 1-day after arriving home, I stripped the bike apart to clean and inspect everything. While cleaning the cassette, (Now, with only 800 miles on it), I noticed that 4 of the teeth on the lowest "52 tooth" aluminum cog were bent and mangled. All 4 of these teeth are in areas where ZTTO has machined what appears to be shift ramps to help the chain be driven up onto the cog. 2 of the teeth have cracks below the tooth where the ramp machining has made the cog very thin below the tooth. Therefore I took measurements: The 52 tooth cog is between 2,1 and 2.18mm thick. Where the teeth are all failing, and the ramps cut into the cog are nominally .71mm thick. This is 33% of the metal left below to the tooth. This is a bad/weak area design!!! FYI - The rest of the cassette still looks brand new! In comparison, My ZTTO 50 tooth cogs on my other cassettes all have ramps that leave 50% of the material below by the teeth with ramps. On this 52 tooth cog, this appears to be a bad design to remove so much material below a key tooth used to help lift the chain onto the cog! (See pics.) yesterday, I wrote the store I purchased the cassette from explaining the problem. They reply was. - "friend the biggest cog is aluminum alloy" This morning, I directly wrote ZTTO explaining the problem and failure. I will share what they write back.