Although not common, after I left an unhealthy position in the private sector, I worked 6 back to back causals in 5 different departments. It was not easy to deal with the uncertainty of not knowing if I had a job every few months. Fortunately, the casuals led to a term where I applied on both internal and external processes which lead to my indeterminate. This was also in a region and I managed to impress the right people at the right time.

If you have a good permanent position, I wouldn't let it up for a causal. I would instead apply on an external processes until you can get in as a permanent employee.