Can a $20 torque wrench from Harbor Freight, etc., be good enough for lug nuts?

For most adults a 4-way lug wrench will be more than adequate to install lug nuts. If the nuts are tightened in a criss-cross pattern in 3 stages ending in maximum exertion they would be reasonably within specification. When customers were concerned about changing a flat without help I used a 4 way to install their wheels and suggested they buy one to carry. The OE dog leg lug wrench is an accident looking for a place to happen.