A simple way of producing good brood combs
In my experience you often get brood combs poorly drawn out if foundation is put directly in the brood box. If there is a nectar flow on it is often easier for bees to extend existing cells than draw out foundation, so you can have the foundation opposite brood on an adjacent comb drawn out well, but opposite where there are food cells the foundation may not be built out because the existing cells are extended to meet it.
If foundation is put in a brood box when the bees aren't in a good condition to draw it, such as when no nectar is coming in, it is late in the season or the colony is weak in bees, they will walk over it and chew holes in it, so when conditions are better they will make a mess of it. I see many poor combs in colonies and I believe these are the main reasons.
Foundation is drawn out well by bees when conditions are right. This is when there is a good nectar flow, the foundation is fresh and the colony is strong. For many years I have used brood boxes as supers, where in a good flow the bees will quickly draw them out, especially on OSR where you can get good combs in 4-6 weeks. If looked after well they will stay in good condition for several years.
Some of the benefits are:-
I use B.S. brood combs that will fit most extractors. If you use larger frames you need to make sure you can extract them.