CTE to Multi-Subject Credential?

Hi all. I have a question I’m having a hard time finding an answer to.

Long-winded Background: as of 9 years ago I have a Bachelor’s in Fashion Design and Merchandising. I spent several years trying to make my way into a corporate retail/fashion position to no avail. Recession, etc. I sort of abandoned the idea that I would ever get to make a career out of it. I decided I was going to return to school to get my multiple subject teaching credential to teach elementary school. In order to make the 50 hour minimum experience working with kids I got a job as a teaching assistant at a grades 7-12 arts school. I like it a lot and have considered changing my credential to another subject so I can teach middle and/or high school. I didn’t get in to a credential program this semester because of a transcript issue but got it resolved for next semester. I also recently passed the multi-subject CSET. Suddenly, last week, I was asked if I’d be interested in teaching costuming at my current school next school year, because the current one is resigning. Needless to say, I am very very interested. However, I’m also a little concerned because I’m not sure if this will be a long-term position for me — the school has some internal struggles it’s dealing with and I’m worried I won’t want to stay longer than a year. The position would require that I get a CTE Credential.

My question is this. If I get my CTE Credential and stay for, say, one school year and then decide to go for multi-subject after all, what would the requirements be? If I already have a Preliminary Credential would that cut down on the amount of school I’d need in order to become multi-subject credentialed?

PS y’all helped me make the decision to take my current job in the first place, so thank you!