Did you know that if you put DXKAX (大玄空挨星) together with XKLFAX (玄空六法挨星), you would end up with some wonderful formulas.
For example, KRY (坤，壬，乙) not only is the permutations of 8 and 2 being repeated, it fits nicely to upper and lower cycle (上元，下元) as well as it also a heaven, earth and man combination (天卦，地卦，人卦). Like wise for JGS (甲，癸，申) and YGD (寅，庚，丁).
And why KRY (坤，壬，乙) is much sort after in period 8 or lower cycle, is also partly because the Flying Stars (挨星) in this set up, points to Triple-Eight (8, 8, 8) in a XKLF (玄空六法) set up. That is partially why KRY (坤，壬，乙) 巨门从头出 talks about 巨门 – Star 2 but is extremely beneficial in period 8.
While the more forceful set up for either upper cycle or lower cycle (上元，下元) are ZMW (子，卯，未), GBX (艮，丙，辛), WYC (午，酉，丑).
The more elusive set up such as XQS (戌，乾，巳), onset it would look like there is no combination of 10 in the 2 numbers, neither is there any Early and Later Heaven links. A closer look, you will notice a 1, 4, 7 (父母三盘卦) linkage.
Year 2021 belongs to the Lower Cycle (下元). Therefore, when using GBX (艮，丙，辛), WYC (午，酉，丑); these sectors need to see mountain, hills, building or receive Qi (氣). And, when using JGS (甲，癸，申) or ZMW (子，卯，未); these sectors need to have a visual on water.
As the area of the the house / apartment getting smaller, this method of flying the stars around is a more efficient way of looking at Flying Stars (挨星).
Hopefully, one day commercial LuoPan (罗盘) – physical or as an Mobile App, can incorporate this 2 ring altogether.
For those who cannot commit this formula to memory, hopefully this quick guide is of help.