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If it's done correctly and Google sees it as if it lives in the subfolder, then yes - it's perfectly fine for SEO. This is a technically tricky solution, though, and would really depend on the capabilities of your hosting provider.

I have the same problem In my moz analytics, but with canonical tag set. I think the moz analytics should detect when a canonical tag is set and ignore the 'sortby, datecut, order' and other inputs, as duplicate contents.