@Angela moved from the US to the UK (and later UK->ES, and then ES->PT), and it was “a whole thing” for sure, with the US->UK move being the most complicated by far.
This was like 13-14 years ago, so a lot has probably changed, but we did freight for most of our stuff (including a lot of music gear). I think we did 100cubic feet or something like that, and it took like 3 months to arrive by boat. The nice thing is that weight doesn’t matter if you’re doing it this way. As long as it fits in the allotted space, it’s fine.
Given how much stuff we had, and what we were willing to pay, freight was pretty much the only option. Air shipping of anything was incredibly expensive etc…
The more delicate/precious gear we brought with us on the flights. So we each had a carry on, and two suitcases. So in that we put mics, ciat-lonbarde stuff, etc… This was post 9/11 but pre-Trump era, so getting checked at the border leaving wasn’t that big a deal, even with weird gear. This was 2007 though, so much has changed…
I was worried about more circuit-bent and DIY looking shit, but that stuff wasn’t a problem at all. Even now when I travel (inside the EU anyways) with that kind of stuff, they don’t bat an eye. Total grain of salt with that though, as our experience was a long time ago.