I too have considered how to Dry Hop in my Fastfermenter 30L methods:-
• With coated magnets holding up 1,2,3 hop bags letting go at various times
• Suspend the Hop Bag from a thin SS wire held up by the Bubbler/grommet
friction ( or other friction methods ) and at the appropriate time...
I'm considering buying the FastFermenter 30l but am reading that there's a serious issue with leeks from lid threads and others has the Manufacturer overcome this problem on current models - BTW who is the Manufacturer I'd like to buzz them on this issue ...joe