Yes @PETELCZYC PAJERO - luke Very much, as long as you see a spot, and convoy order is not closed, U can join the drive! The RSVP mechanism is smart to restrict you, by adding you to WL if u r on your second drive for the week, however, if the drive is not getting full, then WL members gets automatically confirmed depending on their WL number, givimg priority to those who have lesser drives compared to those WL with higher drives for thT week:) ( So you can always add yourself before cutoff time and keep yourself under WL)
In short you are IN for this drive as the RSVP dint put you on WL😁😎