If people want to choose where things land they can do that. Therefore I assume we're talking about a scenario where the items are not known in advance - i.e. they come from a database query or similar. Is there no way to SELECT every Nth item when doing a query? Return a count and select where count MOD N = k? Dump those in a column.
This feels like "I want my layout algorithm to be part of the standard." and if you don't think so, see the part where they also want the equivalent of "colspan = 2" for some itmes - possibly with another pattern to define which ones.
This feels like "I want my layout algorithm to be part of the standard." and if you don't think so, see the part where they also want the equivalent of "colspan = 2" for some itmes - possibly with another pattern to define which ones.