IDA, yes, it's the case for all tech unions. They will help, yes, but mostly to ensure that the contract is legal and up to par with general expectations of the tech sector, work hours, on-call, and so on. But they won't at any point take your position, only help you understand your position so you have more levy in your negotiations. In other sectors you will see that "overenskomster" has been negotiated by the unions, so e.g. all nurses get the same pay based on experience level, the same days off, the same total hours, the same overtime compensation. You thus don't need to negotiate your contract because the union already negotiated a collective contract. No one gets left behind that way. For tech you need to negotiate that yourself and you have to do it each time you change job.

And nice to know they helped with visa. I can't testify for that personally, so I didn't know they offered assistance with that.