I would like to use this but don’t see any way to do so. Is this possible?
Yes, without too much difficulty. Add the accel. Then in the properties panel, set the text to “accel al 150” or whatever. And set the percentage to the desired amount (some math required).
In this example, initial tempo was conveniently 100…
If you don’t fancy doing the percentage calculation, you can drag the end point of the accelerando in the Time track in Play mode - the read-out shows the exact metronome mark value of its current position.
Thanks for the suggestions. When I try that what I get is "accel. al 125 . . . . . . . with the number showing.
If you enter “accel al 125” into the Text field in the Properties panel, that’s what will be displayed. If you don’t want to include the number, just write “accel. al” into the text field. Change the final tempo using the Final tempo % property or by dragging the end point in the Time track in Play mode to the correct tempo - this won’t appear in the text.