This would be a sensible extension of the already existing "Merge Patterns" functionality in the order list's context menu; it could be even as simple as keeping it as a single functionality but prompting the user for a maximum pattern length.

Implemented in r20222. As mentioned, I extended the Merge Patterns functionality from the order list context menu so that it now asks for the target pattern length. This isn't tested a lot, and the code is complex, so give it a try and report any errors you encounter.