It's possible for some extent, see the following answer:
https://tweaker.userecho.com/communities/1/topics/287-ability-to-run-application-or-even-better-trigger-a-media-button-on-clicking-on-empty-taskbar-space
Customer support service by UserEcho
Ideed
It's possible for some extent, see the following answer:
https://tweaker.userecho.com/communities/1/topics/287-ability-to-run-application-or-even-better-trigger-a-media-button-on-clicking-on-empty-taskbar-space