There's a sweet spot for the length of the top link adjustment. There's also a difference in which hole is used on the bracket on the tractor end. For my RFM, the top hole on the tractor is used and the length of the top link is adjusted long enough to allow the mower to droop a bit when the 3PH is lowered, but short enough to pick it up sufficiently. Without allowing some movement the back of the mower would pick up when cresting a hill or bind in a valley..That is done by shortening the top link to use some of the range of motion of the swinging connection point of the mower frame.
The connection point for the top link on my RFM is oriented differently. Here's a picture. It is mounted above the pivot in lieu of below it. There's a tab welded to it that won't allow it to rotate beyond straight up,. The tab bumps into the frame as the lift arms are raised. After that contact is made the mower is raised. At first the front of the mower is raised and when the tab hits, the rear is lifted.
With the top link adjusted for the implement, there's no need to fiddle with it. If the scraper blade is removed in the Spring, the top link is adjusted when the mower goes on and doesn't get touched till the tractor is prepped for snow with the back blade again unless the York rake or something else is pressed into service.