For crafters like me who like to craft their own furnishing, furniture plans are one of our key targets for grinding.
The thing is: farming the new plans with all the base game ones already learnt is really really hard as it seems that the DLC furniture plan have not enough drop rate bonus with respect to other furniture plans.
I am currently farming and out of the many tens furniture plans I farmed since update release I only got ONE single new furniture plan and maybe 2 others from the DLC zone. (I leave out the furniture plans with a single source like the golden Dwemer Glas Armonica furniture plan).
I really suggest (again) to increase drop chance of DLC furniture plans within their zone with respect to the other furniture plans.
PS: To be honest I have the impression that drop rate of DLC furniture plans were actually decreased with respect to before the patch...