Joe, you’ve just triggered a pet peeve of mine.
DO NOT, NOT, NOT change things silently. Ever. If you’re removing a feature (or disabling an underlying HTML capability) do it out loud and don’t make your customer do detective work to figure it out. If Lectora is going to override the user and do something different from what it is told (and I’m putting it that way to make it clear how bad an idea I believe that is), then you MUST, MUST, MUST pop up a big, clear, dialog box that says, “Lectora is removing the ALT tag you put into your course because we know better than you.” (Yes, I’m doing that on purpose.)