The ability to create new tags is granted when you reach a reputation of 150. This isn’t hard to achieve – roughly six good answers. So soon you will be able to create those tags and others will be able to start using them.
Re. the question of being welcome: Here is the meta-SO discussion from two years ago when I was one of the ones suggesting this migration. Back then the Robotics StackExchange was what the moderator who chimed in suggested. I read that as yes, it’s welcome.