Excellent post, just a couple of comments.
A previous administration attempted to force asylum seekers to wait their turn for a hearing outside the country.
Which is really, really stupid. It just makes them some other country's problem, and no other country should be willing to put up with it.
First, it's interesting that Nikkos said "a previous administration", without naming it. It was, of course, Trump 1.0.
Second, international treaties on refugees don't require a country to accept every refugee and there are multiple examples where nations have made agreements that modify which county must handle asylum claims. For example, the US-Canada Safe Third Country agreement specifies that asylum seekers must make their asylum claim in whichever country they arrive in first. If the US and Mexico had a similar agreement, then refugees could not enter from Mexico at all. Trump tried to get Mexico to sign a Safe Third Country agreement, but Mexico refused -- and it probably would have been invalid anyway, since Mexico might not satisfy the requirements of a "safe" country under the US law that authorizes the signing of Safe Third Country agreements.
Instead, Trump signed the "Migrant Protection Protocols" agreement with Mexico, which was the "remain in place" agreement. You said that no other country should be willing to put up with it, but Mexico did formally agree to it, though only to avoid tariffs. Of course, Mexico has declined to renew the protocols in Trump 2.0 (though Trump announced they had, which Mexican President Claudia Sheinbaum immediately denied -- Trump's habit of unilaterally announcing that an agreement has been reached obviously doesn't really work).
Anyway, there are lots of reasons why countries might agree to various limitations on asylum processes to manage refugee volumes, and these agreements are often perfectly valid under international and national law. Trump, of course, doesn't care about legality, or humanity, only what he can get away with.