Assuming boost stays as some sort of a super-upvote/share combo alongside regular up/downvote buttons, here's a UI idea on how to merge it into one unified voting system. App animation + web block mockup en (kbin.social)

I heard that votes have been changed to behave closer to how people would expect, and boost is staying here as well. So I had an idea how to bring it all together in the interface.

Sidenote: you don't have to click the links here, the images are also posted inline in the comments below.

An app (either Artemis or an official one) might use a swipe gesture to visually hint at the relation between upvoting and boosting, as shown in the attached animation. Here's a static app mockup with both swipe levels displayed. I'd also imagine that there should be a setting that auto-upvotes posts when boosting.

And on the web, it's probably a good idea to consolidate all the voting buttons into a single block by adding an additional button at the top.