Please, could you provide more details? So in general with Microflows you are able to maintain multiple entities on a page. If you are interested how this works, I would suggets to take a look for the Academy section. There are some learning paths which could help you.
Is it possible to fill the entity dynamically based on the flow? No.
Or should I definitely have to have 2 copies of the page, one for each entity? Yes.
You may have checked out the option of using a snippet for this, but snippets either show no data, or they show data of a specific entity, not an entity that can vary based on a passed along entity.
What you can do is base the two pages on a building-block. See the AppStore app ‘Atlas-UI’ for samples of building-blocks. That helps a bit, until the moment that you start changing one of the two pages. The other will not also change.