[stefek99]

I know that only US Citizens and Green Card holders can work for SpaceX.

I know that I might not be guy who flies to Mars in the first batch but I definitely want to add mine 2¢.

(mostly around intuitive user interfaces)

An alternative is to open subsidiary in the UK / EU...

[kejaed]

Unfortunately just opening a subsidiary in another country doesn't help, one of the 'features' of ITAR is that it is extraterritorial, so even if you open a subsidiary in another country all the ITAR provisions apply in that country, as well as all the export controls of that country. It's tons of fun even working for a Canadian company.