Due to Google's autoplay policy changes detailed here, we have now started to include allow="fullscreen;autoplay" as an attribute in the iFrames our plugin embeds, for handling YouTube-based content. However, when embedded as part of an assignment submission, the Safe HTML filter strips the attribute. Adding it to the filter explicitly doesn't seem to work, nor does using a regexp with a value of anything - that's how we got around Blackboard's original allowfullscreen attribute problem.
This is now causing issues with a customer, and we're having to create yet another version of our Blackboard plugin. We may also have to update the core product, which is also not ideal.
Is there a sure-fire way to get the new attribute through or is it going to require Blackboard development in some way?