I'm not sure people need checking tbh, but if that is really necessary then the best approach is to have way more routes of applying. The traffickers only have a business because people have no alternative. One would think after several million people died and an economy was ruined, western governments would shy away from Soviet-era collectivism, but when it comes to "managed migration" the state seems to think it can centrally manage the labour market. It's really incredibly daft logic based on nothing more than fear of "the other" which forces them to have to do something because they've whipped up foreigners to be a bogeyman that we need protecting from.
You're a good union man Edge, so I'm sure if one of your members was prevented from getting another job because their residence was tied to it, you might argue that was abhorrent. Heck, you might be even more inclined to think so if they happened to lose their job and no longer retained any right to live where they live. You might similarly think it wrong that someone's employment status is rigorously checked before they're offered a house to rent or given hospital treatment, and yet these are common occurrences for people on a visa.
I was looking at some Italian research recently (
https://academic.oup.com/restud/advance-article/doi/10.1093/restud/rdac003/6527647?login=false if you're interested), and it comes to the not unsurprising conclusion that if we want migrants to thrive then they need certainty about their future. It's logical because we'd want exactly the same for us, yet most migrants are denied that because their status is tied to certain conditions which are, by their very nature, far from certain. It's no way to treat people.