How are weight ranges mentioned for GA airplanes in TCDS? I'm writing software to integrate a weight and balance chart into my website. Most of the Type Certificate Data Sheets TCDS I've read follow the form:

x to y at z lbs. or less
a to b at c lbs.
Straight line variation between points given.

I want to make sure that I test this against more complex scenarios.  Are there general aviation aircraft that have more than 2 "ranges" or are otherwise exceptional that would make for good test cases?  I am only concerned with GA aircraft at this time.
Are there general aviation aircraft that have more than 2 "ranges"


Yes. I happen to fly one (the PA-28 series, TCDS 2A13).
The loading graphs look like this:



Note also that the aircraft is certificated in both the Normal and Utility category, and the weight/CG ranges are different (Utility being a subset of what's permissible for Normal category operations) - so there are two different operating envelopes that must be considered.