It WOULD use them if it had instructions in its research file to research Ship Capture. There is a Boarding Ship design in every one of the AI_Design_Creation files. You just need to tell the race that you want to use boarding attacks to research ship capture. I've done this in my custom ship set with the Terrans and the Jraenar. Since the Terran are also setup to research shield damaging weapons (And I edit their Boarding Ship design to use them) they can have some really effective boarding ships. I haven't actually had a game against them yet, but I'm looking forward to it.