Dear list.
Given the following MWE (could not reproduce with smaller example).
\setuppapersize[A5][A5]
\definefontfeature[base][mode=node, protrusion=quality, expansion=quality]
\definefontfamily[mainfont][serif][EBGaramond][features=base]
\setupalign[hanging, lesshyphenation, hz]
\setupbodyfont[mainfont, 9pt]
\showframe
\starttext
les bestes/ & sus toute la terre/ & sus tout reptile qui bouge sur surete sur la {\righttoleft terre. Dieu} donc crea l'homme a son image.
\stoptext
I notice that LMTX seems to add some small gap at right margin in the 1st typeset line. I attach the pdf I get with luatex and lmtx. The showframe directive makes it more visible.
Joseph