Your comments
1. Project tasks can have users/groups assigned to their team
2. Project tasks can have sub-tasks
3. The option to automatically calculate the percent done was added in GLPI 9.5
A Marketplace feature was added in GLPI 9.5.0 which can show when plugins have updates available.
Done for upcoming GLPI 10.0.8 release.
Timezone support was added in 9.5.0
Implementation started for upcoming GLPI 10.1 release:
You can use recurring tickets with some TODO tasks in the template. Starting in the upcoming GLPI 10.1 release, you can also link assets to the recurring tickets.
Added in GLPI 10.0
Added GLPI 9.5.0
Customer support service by UserEcho
This is possible in the latest version (GLPI 10). I don't know which version it was actually added in though.