Does QC 136 continue east to Ave De Lorimer? There is a km post just to the west.
I'll consult MTQ's online mapping, when I have more time.
The online mapping confirms that QC 136Mon's east end is south of Pont Jacques-Cartier (QC 134), which in turn is south of Av. Lorimier so that avenue doesn't intersect QC 136Mon.
Our practice, at least in Quebec and Ontario, has been to place freeway endpoints at intersections/interchanges, even if the freeway technically ends past the last one. We accordingly placed A-720's east endpoint at Av. Papineau, about 0.23 km south of the non-intersection point where QC 136Mon ends. The conversion of A-720 to QC 136Mon doesn't change that, since QC 136Mon remains a freeway. AIUI, it was decommissioned as an Autoroute because lanes at its west end now are too narrow for Autoroute standards, after the complete reconstruction of the Turcot interchange with A-15 and A-20.
I'm going no-build on this one.