@Ryan *******
, it wouldn't work for OP. You can ask the primary employer to add a secondary workplace/employer. In that case, you still have to keep a working contract with your primary employer to meet an extension and the extension has to be staying with the primary employer. After that, for every single thing you want to do with your work permit, you need to ask your primary employer to support you.
If you want to "change" your employer, you need to cancel your current work permit and apply for a new one.
@Timothy *******
, be careful to manage your work permit.