The only reason a manual migration of each dashboard gadget is required, is because there is no officially supported migration path for:
filters & filter shares
Usually, the Atlassian partner doing the cloud migration for you will address all of these issues using custom tooling (at least for system gadgets). Column Order cloud was built with this scenario in mind and we will happily work together with your partner to automatically migrate Column Order gadgets as well. If you are interested, please reach out to us at support -at- celix -dot- at.