I don't know personally but 197's sounds far too long, even for 4cross lace (7x to high flange)
I think the difference in spoke length on the rear hub is due to the hubs you're using normally being fitted to a bike with multi speed free wheel, therefore giving more spacing on the drive side to allow for that.
I'd try lacing them 3cross with 184's and see what happens
Probably no help but somebody had to say something, good luck