I want to know the answer to the following question:
What is a less systematic example?
All the background I'm provided with is that "However, in the 19th century these were often written via compound characters, pronounced disyllabically, such as 瓩 for 千瓦 or 糎 for 厘米 – some of these characters were also used in Japan, where they were pronounced with borrowed European readings instead.". Is that enough to answer the question?
Answer: no