There was a question yesterday about landing in a wingsuit; the main issue is, of course, the high speed, both vertically and horizontally. One way to reduce speed is flaring; another would be to gain height, which apparently is possible: One of the answers there links a video of a wingsuit pilot ascending from a lake bed to the height of the crown of a dam. However, the climb is modest and the pilot actually accelerates beforehand to fly that maneuver, so that the resulting speed after the climb is probably not lower than usual. In order to shed more speed, the climbing angle would have to be steeper. One extreme case of such a landing is "trampwalling" (see e.g. here): A trampoline jumper is able to land safely on a hard surface at the crest of a parabola where their speed is near zero.
My question is in the title: What is the maximum climbing angle that can be achieved with a (potentially modified) wingsuit? If it is steep enough, a lot of kinetic energy could be shed by climbing, and the landing would be much less dangerous, provided the terrain permits. I have created a little sketch of the idea: