I'm glad you mentioned Bohai. In your article about BHSIC's first expansion (your best work) you estimated the shipyard's launch cadence at 2 SSNs and 1 SSBN per annum. Since I doubt the yard will schedule an SSBN every year - and assuming (perhaps inaccurately) that 2 SSNs could be launched in an SSBN "slot" - I guess that the schedule would be periodic, something like
SSNs launched SSBNs launched Year 1 2 1 Year 2 4 0 Year 3 4 0 Year 4 2 1
More importantly, your 2019 analysis doesn't take into account the second expansion at Bohai. How much do you think that expansion adds to the launch rate?
Moreover, those Yasens are already spoken for. I'm pretty sure the Russian navy will have booked all of Sevmash's capacity for the foreseeable future; I don't see any export potential there. In any event, in Russian hands the Yasens will be doing good work tying up American capacity away from the western Pacific.
My prediction for annual launch rate was very, very tentative.
As for the new southern assembly hall, the way its rails are arranged strongly suggests to me that assembly hall is intended exclusively for SSN sized submarines. Whatever the case, when the second assembly hall starts running, whatever the annual production capacity of the existing eastern assembly hall is, they can add to that basically the annual production capacity of the new southern hall which will likely produce SSNs exclusively.