Let's say I want two columns and then three columns. And I want the posts to be sorted by date. Unless you can tie the two directly together, you would need to offset the 2nd one with 3 columns so that it doesn't start over at 1.
It would be:
1, 2
3, 4, 5
Starting at 3 is not possible without an offset feature. It is a basic feature in other recent posts plugins. Your plugin looks like a fantastic plugin everywhere else so I was hoping you had the feature but I haven't seen any mention of it.
The same concept would apply if you wanted your recent post to be a feature post and then all the others in a sidebar. If there wasn't an offset feature, it would duplicate the most recent post.