Thank you Peter for all of this information and ideas.
My answer to your question is the following: I would try to participate in Hamburg or anywhere else in Germany, Netherlands, Great Britain, France, or Belgium if I got lucky with the timing and could combine the visit with a business trip (as I did on my recent trip to Freiburg). My job requires me to pass through Amsterdam or london about 12 days a year, so there’s a decent chance that the stars will align for me, and I’ll try to attend. But i’ll need some luck.
For me the possibility of meeting Bussler, seeing his set-up, and getting some parvulus or paludicola or ornaticauda would make a visit to Hamburg quite attractive, so that sounds great to me. I’m sure everyone will be attracted to the idea of accessing new species, and this diaspora of the species will serve the project’s purpose — putting these precious eggs in many baskets (hopefully some of them good breeders) to increase their chances of survival. Of course, Hamburg wouldn’t be repetitions for me because I missed the last meeting there. Little said it was fantastic. And wherever the meeting is held, it will be wonderful to meet you and Bussler and Linke, if possible. And hopefully see Hallmann and Beyer again.