How to prevent learner from scrubbing the playbar past where they've already viewed?

Hi everyone! I'm building a project that is a series of Interactive Video slides, with the content hosted on Vimeo. I want the slides to flow from one to the next, which Captivate does by default, but periodically a knowledge check will pop up at the end of a slide which the user has to answer before they can continue. This course is being deployed on a website instead of an LMS, so we can't track scores. Therefore, I can't allow them to skip ahead, so that we know they've answered all the questions correctly by the time they reach the end of the course.

Right now I have the playbar disabled and am using a TOC, which is set up so the user can't click ahead to slides they haven't watched. This is okay, however I would REALLY like to have the playbar enabled so they can scrub backwards and rewatch slides for specific information, without being forced to rewatch a slide from start to finish each time they go back to a viewed slide, which is the case if you click to a previous slide using the TOC.

Is there an advanced action or something that I can use to prevent forward scrubbing of the playbar? I know it's possible because I have a tool created by a previous developer at my company that packages video into SCORM files indpendent of Captivate, and this is one of its default features. I am using the current build of Captivate (11.5.1.499) on Windows 10.

I know that there used to be a hack simliar to this that worked in an earlier version of Captivate, but that stopped working with this newest build. I'm not a proficient enough Javascript user to work this out on my own. Please help!