Hi Hurtuk ,
Thank you very much for this.
ATUM is fully compatible with WC bookings, however, I think the feature you are requesting is not possible to achieve. As far as I know it was not possible in the past, so not sure I understand what you mean in the old version?
You can set the low stock threshold that will inform you about the booking coming to an end. You can use the out of stock threshold to block it after the 300 bookings as well.
Just set stock of the booking to 300, or am I misunderstanding?
Pavel