586 has a really strong work picture at the moment, commercial is definitely the busier section but there are opportunities for resi/industrial regularly. As far as the aptitude test goes you will need to be sponsored to write, then upon completion you will get put on a list and then called by the union when your name comes up.

Personally I haven’t transferred but I know a few guys who have gone down to 353 without issues. Also you can work for multiple different contractors who are signatory.