Dev environment for Teams Voice

Hi 

I am a Cloud specialist that looks after various Teams environments. Recently I have been migrating a lot of my clients from Skype for Business to Teams, as well as I am just about to take the MS-721 exam. 

I have two test environments from the M365 Developer, it is very useful and I am able to re-created a lot of my clients scenarios as well as it is extremely handy for exam study. 

However one limitation is Teams Voice, it would be useful to the capability to have a handful of numbers and a calling plan for a temp basis just to look at the live creation of call queues, auto attendants and the other features you would have around Teams voice capability. I have tried to get a trial license however it does not work on the Dev environments. 

Has anyone one found a way to make a temp test environment or is this something Microsoft can look into?