After a bit of contemplation, I went ahead and made a whole bunch of dual gems. I’m really pleased with the results!
My main advice to everyone is to make sure you leave in a full set of purely ATK gems in your gear, since the only dual gems with ATK in them are ATK + Crit.
There are a lot of different directions you can go with these new gems, but make sure to look at the synthesis page first, since the combination options are pretty limited at the moment. Here’s my “before and after”: