Book it in advance
My experience is the following:
I was able to book the trip and even get into the whatsapp group to meet the trip peers 1 week before the flight. Afterwards I received a call stating the flight was overbooked and since I was the last one joining they need to cancel my vacation. I received the money back but if you are a professional operator you don’t keep the platform open until the last minute to try to full fill the group and later cancel it.
I received a discount of 100 euros for the next trip but my vacation is gone, even proposing to pay extra money for the bookable flight (open in the airline) was not an option.
My suggestion is simple order it with plenty of notice, otherwise skip it. A professional operator doesn’t do that mistake.
I believe they will improve but not for me
Best regards