Although "everybody knows" the syntax of .cfg files (they are good old .ini files), the devil is in the details. There are multiple variants of the .ini format. Just read the Varying features section on the Wikipedia page. Could we please have an exact specification of the format as used by MSFS? (Or is the plan to switch to JSON soon anyway?)
Apparently there is no line continuation possibility. Having a such feature in the file format would be very nice. Just think how much easier it would be to edit this:
mach_hi_corrected_commanded_ne_table = \ \ 0.90 : 1.0 : 22.57,\ \ 0.00 : 62.0 : 82.50,\ 0.42 : 77.0 : 95.40,\ 0.51 : 80.2 : 98.50,\ 0.61 : 84.8 : 101.10,\ 0.70 : 89.1 : 103.10,\ 0.79 : 92.2 : 105.70,\ 0.93 : 96.0 : 108.06,\ 1.00 : 98.2 : 108.06
mach_hi_corrected_commanded_ne_table = 0.90:1.0:22.57,0.00:62.0:82.50,0.42:77.0:95.40,0.51:80.2:98.50,0.61:84.8:101.10,0.70:89.1:103.10,0.79:92.2:105.70,0.93:96.0:108.06,1.00:98.2:108.06
Don't you think? (This is just the table in question from some existing aircraft, slightly edited to have less pointlessly precise values.)
Sure, with unlimited resources the simulator's Dev Mode would have a graphical tool to manipulate actual underlying curves, instead of you having to tinker with numerical tables intended to describe such curves, but I am not holding my breath.
Also, any developer with some scripting experience will eventually get bored and come up with some workflow where the .cfg files they write are passed through some suitable preprocessor or filter, and that then enables them to write tables like that on multiple lines with nicely aligned columns.
Personally I use the venerable m4 macro processor for this at the moment. (Using a full-fledged macro processor has the additional benefit that you can use macros for instance to turn measurements in inches or metric units, taken from an aircraft's specifications or drawings, into the feet that MSFS wants.) But it is a bit sad that all serious aircraft developers need to duplicate the effort.