Generative Components - TBM Tunnel


I am catering 16km TBM Tunnel, and I have two main issues.

1. Length of the tunnel discovers GC limitations. Computing tunnel build from rings (ring is created as node element build from build from 7 segments) takes 12 minutes for 1km distance on fast computer. It is impossible to create full 16km length ,hence model has to be split. Is there other solution for that? And is there a plan for multi core CPU support? 

2. Creation of Key Block or Segment from WALL. Key element looks like on picture below

For normal Segments (C shaped) I am using Wall node created on arch. No problem here. I am using wall as I need to have all project metadata from catalog.

Problem is with key element. I have to cut (node Wall by cut) C shape segment on both side, by rotating two planes at the end of the segment. I use line as cut tool and feeded to CuttingProfile makes the software crash. When I do not rotate planed I see some cut preformed - but software again fezzes and crash. 

Is there a better way to created tunnel key element (tapered C shaped wall) from Wall than by cut?

Software version as required on the project: