Open Evening is an event like any other, and over and over it has been clear that members do not want to host it as it is currently structured, and yet a very small minority of the membership wholeheartedly refused to accept this fact and instead keep thrashing this dead horse that is Open Evenings.
From my perspective we are look at this completely wrong, creating rules and trying to enforce volunteering will not work, we have 153 members, less than 1/3 of those are active in the space in any regular way, and a third don’t even have a key fob.
People don’t volunteer because they don’t have time, don’t want to or aren’t using the space, sending out an automatic email with your schedule for them will fail and we’ll watch watch as week after week people fail to turn up, or send emails to the directors cancelling. You can’t treat people like employees and expect them to turn up, they will ignore you, or leave.
Incentives might work, but they need to be a bonus on top of membership, not a stumbling block to full use of the space, you could look at how Building Bloqs uses an internal currency.