Time Estimation only for specified groups

[KaiKruppa]

Given Situation:

Let's say 3 types of Users(usergroups) have to do with an issue:

- Customer Agent

- Supporter

- Developer

Let's say the Customer Agent creates a Ticket (of Type Development) for a Job which the developer should care of.

The Customer Agent and the developer have estimated that this job needs 3 hours of working time.

Tracking is enabled, estimated time is set.

Wished Workflow:

My wish is, that every employee/user of every user group can track his work onto this ticket.

Second and more imported to my wish is, that only the tracked time from the developer is using the estimated contingent of this kind of ticket.

I know that you can manually adjust the estimation or choose if you want to use the contingent, but i want that this point is either disabled from the beginning for everyone, so that you have to actively choose that you want to use the contingent or much better: the tracked time of the group that this kind of ticket is for automatically use the contingent, while the group of everyone else does not.

I already took a look to User permissions according the Time Tracking but haven't found a way to realize what i was looking for. (https://confluence.atlassian.com/adminjiraserver072/managing-project-permissions-828787763.html) 

Does anybody have helping information about this topic?