format multiple conversion characters with one conversion specifier

I am writing on suggestion from remkop@yahoo.com in https://stackoverflow.com/questions/50311762/log4j-set-class-and-method-summary-length-in-pattern 

I would like to format multiple conversion characters with one conversion specifier.

As Remko explained, it is currently not possible

No, each modifier applies to one conversion. But Log4j could add a new converter that means what you want. You can propose such a new converter on the mailing list or issue tracker

Would it be a useful feature to add to log4j2 ? Would it be hard to implement ?

EG

I would like to set summary length of class.method.line with

%-60.60CML

It's not possible now. Below what doc states

https://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html

Each conversion specifier starts with a percent sign (%) and is followed by optional format modifiers and a conversion charact*er*. The conversion charact*er* specifies the type of data

The pattern parser knows when it has reached the end of a conversion specifier when it reads a conversion charact*er*.

It writes only about single conversion character, I would like to modify multiple conversion characters with one conversion specifier.