Re: Convert B dependent permit to independent one.
I'm not 100% certain the advice being given to the OP is correct. Already being employed here can help one get an independent permit.
I have an American friend here on a B-permit who divorced from their EU spouse but wanted to stay in CH. They'd been working for a Swiss firm for a few years in a reasonably technical job. Their employer was successful in application for a new permit, giving the justification that it was a specialist position, and after several years of on-the-job experience my friend was already the most qualified person to be working that job. There was no advertising of the position looking for other Swiss or EU candidates, and my friend remained in the country and continuously employed throughout the permit application process, despite the EU spouse having already left the the country.
So I guess whether or not your job can help you largely depends on what kind of job it is. If it's a specialized position you might be in luck, if you do data entry or work as a waitress it's probably not going to work.