(1) \setupbodyfont[somebodyfont,12pt]
\definefont[chapterfont][somefont sa 1.728]
\setuphead[chapter][style=chapterfont]

gives a compile error at \chapter{chapter title} :

! Font \**chapterfont**:=somefont at 20.736pt not loadable: metric data not found or bad

However

\setuphead[chapter][style=\tfc\somefont] works OK.

\setupbodyfont[somefont,12pt] also work OK, while

\setupbodyfont[chapterfont,12pt] defaults to LM font

Uh ?

(2) fc-list output extract

Times New Roman:style=Regular,Normal,obyčejné,Standard,Κανονικά,Normaali,Normál,Normale,Standaard,Normalny,Обычный,Normálne,Navadno,thường,Arrunta
Times New Roman:style=Italic,cursiva,kurzíva,kursiv,Πλάγια,Kursivoitu,Italique,Dőlt,Corsivo,Cursief,kursywa,Itálico,Курсив,İtalik,Poševno,nghiêng,Etzana
Times New Roman:style=Bold,Negreta,tučné,fed,Fett,Έντονα,Negrita,Lihavoitu,Gras,Félkövér,Grassetto,Vet,Halvfet,Pogrubiona,Negrito,Полужирный,Fet,Kalın,Krepko,đậm,Lodia
Times New Roman:style=Bold Italic,Negreta cursiva,tučné kurzíva,fed kursiv,Fett Kursiv,Έντονα Πλάγια,Negrita Cursiva,Lihavoitu Kursivoi,Gras Italique,Félkövér dőlt,Grassetto Corsivo,Vet Cursief,Halvfet Kursiv,Pogrubiona kursywa,Negrito Itálico,Полужирный Курсив,Tučná kurzíva,Fet Kursiv,Kalın İtalik,Krepko poševno,nghiêng đậm,Lodi etzana

With the following typescript

    \starttypescript[serif][timesnewroman]
        % --- MS TrueType Core Font ---
        \definefontsynonym[Dummy][name:Times New Roman][features=default]
        \definefontsynonym[DummyBold][name:Times New Roman Bold][features=default]
        \definefontsynonym[DummyItalic][name:Times New Roman Italic][features=default]
        \definefontsynonym[DummyBoldItalic][name:Times New Roman Bold Italic][features=default]
    \stoptypescript
    \starttypescript[serif][timesnewroman][name]
        \definefontsynonym[Serif][Dummy][features=default]
        \definefontsynonym[SerifBold][DummyBold][features=default]
        \definefontsynonym[SerifItalic][DummyItalic][features=default]
        \definefontsynonym[SerifBoldItalic][DummyBoldItalic][features=default]
        \definefontsynonym[SerifSlanted][DummyItalic][features=default]
        \definefontsynonym[SerifIBoldSlanted][DummyBoldItalic][features=default]
        \definefontsynonym[SerifCaps][Dummy][features=default]
    \stoptypescript
    \definetypeface[myBodyFont][rm][serif][timesnewroman][default]

\bf displays in bold italic (??) so something is wrong/missing. Seems to be something with the style=... stuff. Fruitlessly searched the wiki and mailing list archive.

Alan