Now that my software designer mindset is active again: to disable the ALT tags is to favor usability for the screen-reading audience over usability for the sighted.
Instead, why not have features for both?
Above, you write, “Hover text is lost, but it is possible to make your own hover text in Lectora if it is absolutely necessary.”
So, in an accessible title, have Lectora actually pop up a dialog box that says, “In an accessible title, ALT tags are removed because they interfere with screen readers. Would you like Lectora to display your ALT text as hovertext instead? Yes No”.
Easy to code and avoids the whole problem, for 99.9% of cases.