There is no "protection" and I'm not sure what you are asking about "protecting".

If you are on good terms with them, and aren't burning the bridge, there should be no issue. Just make sure you stay in touch with the responsible engineer at your current job, in case they also leave their position.

Engineers are expected to act in a responsible and professional manner, and that includes signing off reference documents for the younger ones I've done a few of them ...

I guess I was thinking there had to be some policy for this exact situation that would protect me in some way, otherwise I am at the mercy of an employer that I left. I guess I just wouldn't be surprised if they gave me trouble in 1.5 years when I come to them asking for signatures on reference documents.

Though your employer might be holding a grudge now, he will likely have gotten over it in a couple years once you need him to sign a few forms.

Additionally, as Brian mentioned, don't doubt the old grumps ability to behave professionally.

As a professional you are supposed to act in a courteous manner to other professionals. This means not holding grudge that can impede another's progress due to personal feelings.

As for reference documents on your experience it is required to provide an accurate characterization of the applicants abilities during your time working for that employer. Probably not going to be as flattering as a good bye lunch or staff gathering.

The first stage of site investigation is desktop and it informs the engineer of the anticipated subsurface conditions. By precluding the site investigation the design engineer cannot accept any responsibility for providing a safe and economical design.

I can't recall the specifics enough to look it up but I seem to recall a thread here a while back where exactly what you worried about happened. As I recall, they were trying to negotiate with the state board to go around the errant PE but I don't remember if they were successful. In short; you may still have options but it will be way easier if the PE plays ball; and most will, even if they have a personal issue with you.

One caveat; if their issue is they think you're an unqualified or unethical engineer then they actually have a duty not to recommend you.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL) Structural Engineer (IL, HI)
American Concrete Industries https://americanconcrete.com/

How large is your current company?
If a large company that becomes easier since your PE paperwork is signed by your supervising PE, not the company. Be sure you talk with them before you leave stating that you would like them to sign your PE paperwork for the time you worked there when the time comes.
If it is a small company, they should understand your need for the PE license and be cooperative in signing it.
Don't burn any bridges!

"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

It's a small company. Haha it seems like a fine line. I have been in a really good mood because I am excited for my new job. I think it came off as arrogant and smug yesterday so I am gonna have to tone it down. Not trying to burn any bridges, just trying to get through the week.

I contacted the Utah Department of Professional Licensing. She sent me a form to have them fill out before I leave. I was under the impression that they had to fill it out at the appropriate time and send it themselves but I guess not.

There may be factors not mentioned. However, suppose it turns out to be a negative report. No changing that now. However, in time you will get over any current problems. Chalk up any problems to experience and what not to do again..