It doesn't have to be a "hack". Most modern devices would support it just fine. The main problem is the older kindle devices that only support the mobi7 format.

It doesn't have to be a "hack". Most modern devices would support it just fine. The main problem is the older kindle devices that only support the mobi7 format. An author is likely to get dinged on reviews if formatting on older eink devices is poor. So in practice the lowest common denominator wins out...