How do you set the display scale?

I'm using a HiDPI display, and everything displays very tiny when using cage.

I've been digging through various closed issues and pull requests in this repo, and the furthest I've managed to get is seeing vague gestures at wlr-output-management without any information on how it can be used in reality.

I've tried messing with wlr-randr and kanshi and haven't gotten anywhere, so clarification would be greatly appreciated.