How do you get the buttons within the edge's left and right margins while
keeping the button width=\rightedgewidth ?

\setuplayout[
 rightmargin=0mm,
 rightedge=15mm]

\showframe

\def\myButtons{
    \vtop {
  \interactionbuttons[
   width=\rightedgewidth,
   height=20pt]
   [StartMovie]
  \blank
  \interactionbuttons[
   width=\rightedgewidth,
   height=20pt]
   [StartMovie]}}

\setupinteraction[state=start]

\setuptexttexts[edge]
 [][\myButtons]

\starttext
test
\stoptext

Best,
Alan