Maybe if you organise it more regularly, a day will be enough for a hackathon-- I heard about https://open-x-day.org/ in companies being a very nice vehicle to share knowledge and discuss..

Also sounds to me like some kind of https://en.wikipedia.org/wiki/Microdegree (in german https://de.wikipedia.org/wiki/Micro-Credential )

fine idea to give it an embedded look and to shift to the process instead of just the product. This might encourage to fill the timeline and take on!

Check out dribdat/wiki/Guidelines and Hackathon canvas (@ClaudiaFricker)

Reminds me of https://www.meetup.com/Hackergarten-Basel/