My organization uses QuickBooks Online Plus, and implemented the Classes system. We also use Campaigns as Campaigns in CiviCRM, so all the previous solutions do not work for us.
So, we came up with a possible solution, but it would require a change to the export function. We are thinking that we use the Financial Account name to hold both the Account Name and the Class Name. For example, we have two Financial Accounts: Member Dues:National and Member Dues:Chapter. The colon separates the account from the class. But for this to work in the export, I need to get the journal entry transaction before it gets written.
We can't use the Campaigns feature for this because we do have fundraising campaigns as well as petitioning and membership campaigns. The name seems to be our best solution, but we're not sure how to get it to work. It's beginning to look like it would be a patch to core. ::shudder::