While not in engineering, my father went through a like experience. He was a stevedore. As such he had a place in the Longshoreman's union. He was the third highest man in his gang, and was their crane operator. The company they loaded for ask him to come to work for them, taking care of all their cranes. Going from the union to work for the client is known as becoming a Company Man in the stevedore trade. [as in other trades as well] There was a goodly increase in pay, and the promise of not working weekends and holidays. But he would have a set salary, not get paid by the hour. They also said he would have two full time helpers.
He took the job, but only after getting it in writing that he wouldn't loose his place in the union if it didn't work out. The company didn't keep any of their promises about hiring him helpers. He had one part time kid. Daddy was in his 50's by then, and crane maintenance is very hard work. [if any of you have ever greased your yard tractor, just imagine having several hundred feet of 3' cable to grease weekly. And that is just one crane]
He was working more hours than he had when in his old gang. And when you think about the added tax bite, the per hour wage wasn't that much better than before. After about 8 months he quite the company and went back to his old spot in the gang. Where he worked until he was 62.
Staying put until you decide to leave would be the safest course of action.