Some things won't come over in the same way, as the feature might be slightly different in the new product.
For example, it's likely that the new product will use topic-style private messages (like Classic), so for UBB.threads users, their standalone private messages will be imported into topics.
Other features might be removed or changed in some way as to make certain settings invalid (like the complexities involved in the Recent Visitors controls).
Porting the Classic model of private forum access - and password protected forums - is also going to be very interesting. We'll have to decide on either the express permission model or just shove everyone into a group upon import.
(I speak in generalities here not because I don't know what's going on, but because I don't want to give you guys information that may later become invalid.)
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