Spacing of combs seems to be confusing for people. Brood is a fixed space. A brood cell is a given depth (about 1/2" which makes a comb that is about 1") and, if the bees have their say, a given diameter of about 4.7mm to 5.1mm. Those combs are, if the bees have their say, about 1 1/4" (32mm) on center. If you space them wider, you'll have problems. How much depends on how much wider. You can usually get by with 1 3/8" (35mm or the standard width of a Hoffman frame). But with foundationless they may cheat that a bit on each successive comb until they are getting off. Making it wider than 1 3/8" in the brood nest is just asking for problems. On the other hand honey is not a fixed depth. I can vary from 1/4" to 2" or even more in depth. Typically if you give them only 1 1/4" with comb guides, they will probably ignore the guides and make the combs wider for honey. Typically if I give them 1 1/2" they are willing to accept that, but sometimes they will cheat them even bigger. 1 1/2" on center is the typical spacing of 9 frames in a ten frame super.
One of the things get gets bees off, is when the beekeeper decides to evenly space the combs in the brood box. This increases the standard Hoffman spacing if 1 3/8" to closer to 1 1/2". Even worse if they put 9 frames in a ten frame brood box.
The most important thing to understand about foundationless is that bees build parallel combs. So one bad comb leads to another bad comb. One good comb also leads to another good comb. So if you can get a good straight comb you have a better start that is more likely to result in more good combs. Two straight brood combs are a gift. You can now put an empty frame between those and get another perfect comb. All beekeeping is an art. You have to look at the situation and adjust. It is also a science, in that understanding what the bees will build for a particular circumstance will help you make your decisions. Understanding that they build parallel combs, understanding that brood combs are a fixed thickness and that honey comb varies and that honey is typically thicker than brood are facts that will assist you in making your judgments.