\startluacode
    fonts.handlers.otf.addfeature {
        name = "kern",
        type = "pair",
        data = {
            [0x0153] = { [0x0301] = { false, { -140, 0, 0, 0 } } },
        }
    }
\stopluacode

\setupbodyfont[cambria]

\starttext

    \unexpanded\def\oeacute{\char"153\char"301\relax}

    b\oeacute f

\stoptext
