Although Pleco does add erhua (i.e. adding the rhotic coda or 'r' sound to the ends of some characters as indicated by a trailing 儿 character) to some entries and includes it in some example phrases and sentences, support for erhua in Pleco is scant. I bought the Xiandai Hanyu Da Cidian add-on and expected it to indicate erhua at the definition (sub-entry) level, perhaps that's because my paper copy of Xiandai Hanyu Cidian has this. I'm not sure if the Da Cidian paper copy is different. Here's generally what I would like to see. Take for example the character 串 chuàn. The first definition is for the verb "string together". But there is also the definition of this character that is a measure word for "a string of things". Erhua can be added to this measure word, so this definition entry would indicate that with something like “（～儿）” at the beginning of the definition. If the Xiandai Hanyu Da Cidian doesn't provide this information, I'd still like to see either the Pleco C-E or another add-on dictionary provide this useful information.