Although this is pretty easy with LaTeX:
\usepackage{harfload}
\setmainfont{font}[RawFeature={mode=harf}]
I have no idea of how to make it work with context. I've tried the following with a test file (a simple \starttext .. \stoptext document):
context tests.tex --engine=luahbtex
And this happens:
mtx-context | run 1: luahbtex --fmt="/home/coragyps/.texlive2019/texmf-var/luatex-cache/context/a86c089b384a3076dc514ba966a1fac9/formats/luatex/cont-en" --jobname="tests" --lua="/home/coragyps/.texlive2019/texmf-var/luatex-cache/context/a86c089b384a3076dc514ba966a1fac9/formats/luatex/cont-en.lui" --c:currentrun=1 --c:engine="luahbtex" --c:fulljobname="./tests.tex" --c:input="./tests.tex" --c:kindofrun=1 --c:maxnofruns=9 --c:texmfbinpath="/usr/local/texlive/2019/bin/x86_64-linux" "cont-yes.mkiv"
This is LuaHBTeX, Version 1.11.2 (TeX Live 2020/dev)
system commands enabled.
(Fatal format file error; I'm stymied)mtx-context | fatal error: return code: 256
What should I do? Thank you in advance