KMF Quants

Should I really practice the KMF questions? Or the ETS materials and Manhattan lb is enough for 170ish quant.

What exactly is the KMF questions?

The Chinese website that provide comprehensive practice problems on GRE Verbal, Quant and Writing.

I’m not aware of those set of questions.

Although, the Official ETS material, the Manhattan 5lb are great for practice.
You can also refer to the ETS Big Book, and the questions on the GregMat website too.
These are also amazing sources of practice material.