HHHH, maybe your rear axle is slightly bent, or your cog isn't running round for any other reason? I doubt it has anything to do with BB or chainring as your ratio would spread the uneven chaintension/wear across the cog.
@MileEater started
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HHHH, maybe your rear axle is slightly bent, or your cog isn't running round for any other reason? I doubt it has anything to do with BB or chainring as your ratio would spread the uneven chaintension/wear across the cog.