Limiting the amount of surprises you get when developing a large-scale Drupal project is always a good thing. And to that end, Acquia's BLT (Build and Launch Tools) wisely chooses to leave Drupal VM alone when updating BLT itself. Updates to Drupal VM can and should be done independently of install profile and development and deployment tooling.

But this creates a conundrum: how do you upgrade Drupal VM within a project that uses BLT and has Drupal VM as one of it's composer dependencies? It's actually quite simple—and since I just did it for one of my projects, I thought I'd document the process here for future reference: