What are the best Team Role settings for a Tester?

I have multiple testers in my project and I would like to give them a separate team role. I have given them the Developer role so they can download the app and run and test it locally with their own testdata. But it seems that granting them download and run rights in Studio Pro also gives them commit rights. Is there an option to let them do that but prevent them from committing? 
1 answers

There is no option to prevent a role from committing to the Mendix teamserver.

Understand your wish though.

What I would do is to create a branchline which is used by testers. So that if they would commit, it is isolated. 

Secondly, what kind of test are they running? If it is just frontend testing, they dont need model access. Deployment to acceptance and granting them access to the app on acceptance would be sufficient.

Third, if you want to perform unit tests and such, I advise to look into Menditect