Based on some long term tests on YouTube it seems to me BYD would likely get sued to oblivion if they didn’t be honest with their range claims and charging times with the US market. Most Americans tend to expect a lot from their vehicles - BYD might actually have issues when reviews and quality issues become apparent. Then again panel gaps on Teslas didn’t stop buyers from paying more for less, though competition was lacking, and now a recall because the wrong adhesive was used on the trucks is a laughing stock.
I don't know about the CLA, but I have an A-class (admittedly, ten years old) and a BYD Seal, and the build quality/feel of the Seal is around the same as Mercedes cars, except for half the price. I've test-driven some recent Mercedes cars, and both the BYD and the Mercedes (as you'd expect) felt premium.
I really do like BYD's approach of "everything is standard, no addons", compared to MB's nickel-and-diming you on the features, though.
BYD measures range using the WLTP standard in China. If they sold in the States they'd use the EPA measurement, which would result in lower numbers. As long as they accurately applied EPA they could show good faith and would likely prevail in a lawsuit.
I am eager to see a BYD compared to a new MB CLA.