@Joseph: clarification of the green light: While in Shabbos mode, the green light is on to definitively indicate that no internal LED transmitter will be pulsed in the near future (e.g. within the next five seconds) so it is “safe” to move the plastic blocker.
Once the red warning light comes on (also in Shabbos mode) an internal LED may potentially be pulsed in the near future though (as detailed in my earlier post) this Transmission event may be randomly delayed (i.e. the pulse will happen and not safe to move- although e.g. it could be up to 30 seconds later).