That looks cool! I had some Unity editor scripts for switching targets and initiating builds https://github.com/technicat/fugueditor but yours sounds more seamless (and I haven't used mine since last year so I don't know if they still work). Another option is Unity Cloud Build which was convenient for not tying up my underpowered Mac in long builds, but sometimes the builds queued for for days and if something went wrong I could never tell if it was a problem in the cloud build, Unity Collaborate, or something else...