Negotiating a new role at my company

I've been working at my current company for 5 years and have been looking at internal opportunities to grow and move up. This is something our company supports and encourages.

I applied for a role that would give me a 2 level promotion if I get it, but the caveat is that it's a 6-month contract. Context about contracts at my company, new roles, especially ones that never existed before, start on contract of 6 months as a probationary period of sorts. At the end the decision is made to extend, terminate or transition the role to regular full time. That's how I started when I joined.

So I'm a regular full time employee, with all my benefits and vacation time earned. And if I transition to contract, I would potentially lose all that.

My question is, would it be unprofessional to potentially go through the interview process and try to leverage my experience at the company to try and get the role changed to regular employment? Obviously for security reasons, I don't want to give up stability, benefits, pension plan, etc. for a 6-month contract that may be terminated.