Sorry for the delay in replying. You can right click each one to hide them, though this very time consuming.
A workaround would be to
- select the whole passage.
- Right click>Tempo>Make tempo marks abbreviated.
(- optional step. If you want to keep any main tempo changes visible, then individually right click them, then: Right Click>Tempo>Make Tempo Mark Not Abbreviated)
Then RIght Click the whole passage again>Tempo>Hide abbreviated tempo marks.
All your tempi will play back but will be hidden.