There is quite a bit you can do. Use the search box (top right) particularly on why bees not using flow frames.
This can be a start. How to encourage bees to fill the Flow Frames
Edit: PS You don’t necessarily have to have two deep broods. Probably it would be 50-50 with those using one brood and those using 2 broods.
Two broods are important if you have long cold Winters and the test is: What do the professional bee keepers use in your area. Do they use 1 brood to a stack of supers or 2 broods to a stack of supers?