It seems that margin notes when called from inside \startcombination..\stopcombination do not reach the margin of the paper. Instead they use a margin inside the combination.
Is that as intended or unavoidable?
It was my objective to have them at the edge of the paper.
See minimal example below.

% Testing margin notes from inside combinations.
% Margin notes do not leave the combinations box.
\setuppapersize[A6][A6]
\starttext
\setupcombinations[location=middle]
test\crlf
\startcombination[2*1]
{abcdefg\inright{m1}}{l1}
{abcdefg\inright{m2}}{l2}
\stopcombination
\crlf
\stoptext