Gradual tempo changes indicate a change in tempo over a defined period of time, such as rallentando, which indicates slowing down, and accelerando, which indicates speeding up.
Gradual tempo changes are considered a type of tempo mark in Dorico Pro, meaning you can input them in the same ways as for tempo marks.
Because gradual tempo changes have a different metronome mark value at the start/end, you can change the final tempo at the end of individual gradual tempo changes.
In Dorico Pro, you can show gradual tempo changes with different styles, such as with a continuation line or with syllables spread across their duration. You can also show gradual tempo changes with different line styles, such as dotted or dashed.
You cannot change the angle of gradual tempo changes.