All good advice. Don't forget to set the focal length on the camera body (C33, C330/f/s), otherwise the parallax bar will be wrong!
The lenses are separated by 50mm vertically, so if you do nothing, the taking lens is going to image the area 50mm below the one you composed. At closest focus the 135mm will image an area 250mm x 250mm (rounding slightly). So parallax will put you off by 1/5th of the vertical. If you are working with the camera horizontal you can get the 50mm rise from a tripod center column, but there is a risk or rotating the camera unless it is a geared column. If a camera is tilted, but the column is vertical, the geometry probably won't work.
With still life subjects you can use a viewing card. Set it up to match the finder, then drop it (and your eye) 50mm to line with the taking lens. That gets rid of the vertical parallax at the expense of introducing about the same or more lateral parallax. The Paramender was made for a reason! Sometime with still life you can jack the subject up and down 50mm. At 1/5th of the frame you could just generously frame the subject on negative film.
Even with the Paramender you have to develop a routine of putting the camera back in the lower position after each shot. otherwise you are trying to correct an already corrected position.
Ask me how I know this!