Dear gang,

Consider the following typescript template:

\definefontfeature
  [myfont-tf-sc]
  [mode=node,script=latn,language=dflt,trep=no,
   protrusion=quality,expansion=quality,
   compose=yes,combine=yes,tlig=yes,
   kern=yes,liga=yes,onum=yes,cpsp=yes,smcp=yes, % smcp activie
   trnsl=force]

% synonym mapping
\starttypescript [serif] [myfont] [name]
  \loadfontgoodies[myfontlfg]
  \definefontsynonym [Serif]           [MyFontRegular]    [features=myfont-tf]    
  \definefontsynonym [SerifItalic]     [MyFontItalic]     [features=myfont-it]  
  \definefontsynonym [SerifBold]       [MyFontBold]       [features=myfont-tf]  
  \definefontsynonym [SerifBoldItalic] [MyFontBoldItalic] [features=myfont-it]  
  
  \definefontsynonym [SerifCaps]           [MyFontRegular]    [features=myfont-tf-sc]    
  \definefontsynonym [SerifCapsItalic]     [MyFontItalic]     [features=myfont-it-sc]  
  \definefontsynonym [SerifCapsBold]       [MyFontBold]       [features=myfont-tf-sc]  
  \definefontsynonym [SerifCapsBoldItalic] [MyFontBoldItalic] [features=myfont-it-sc] 
\stoptypescript

% font mapping
\starttypescript [serif] [myfont]
  \loadfontgoodies[myfontlfg]
  \definefontsynonym [MyFontRegular]     [file:MyFont-Regular] % [features=myfont-tf]
  \definefontsynonym [MyFontItalic]      [file:MyFont-It]      % [features=myfont-it]  
  \definefontsynonym [MyFontBold]        [file:MyFont-Bold]    % [features=myfont-tf]  
  \definefontsynonym [MyFontBoldItalic]  [file:MyFont-BoldIt]  % [features=myfont-it]
\stoptypescript

As is well known, \sc selects the small caps only from the Serif font, not from SerifBold etc. But MyFont has smallcaps for every style. So in the typescript we make that explicit and apply the smcp=yes fontfeature to SerifCapsBold etc. 

But this does not work: \sc still only applies to Serif or SerifCaps.

Now I can load a goodies file myfontlfg and do something like this:

local smallcaps = {
    smcp = yes,
}

But that does not change the behavior of \sc.

Yes, there is an easy workaround:

\definefontfeature[smallcaps][smcp=yes]
\define\sc{\addff{smallcaps}}

This works for all styles that have the smcp feature, but I don't like having to redefine a system command.

So the questions are: 

1) Is there a recommended\better way to get \sc to work across all styles?