I do write some code - but this, as simple as it may be for someone who codes everyday - has defeated me.
The method you suggest is along the way I had been working.
I would think that for the sake of accessibility this would be something that would be worth the attention of the plugin dev's.
I am in the planning stages of a site that will have multiple authors and event forms etc.
It would be a nightmare to have to add alt text to images uploaded by hand.
A requirement of the site is that it meet accessibility standards.
Could you bring this to the attention of the dev's please. I think it would make an excellent article for your website and or You Tube channel.