I assume that inter traffic group table access was somehow possible before 11.4 and now it's not. I can see benefits of session table space partitioning per TG but kind of read only access (lookup) could be implemented - as it seems to be fastest way to exchange data between iRules in different TGs - but well, we have what we have and have to figure out some way to use it :-)
Great explanation about difference between network connection and session table and how mirroring works for both!
Thanks for help (again :-)
Piotr