Anyways, back to "conjecturing":
1. Quoting Peter Lim's research about Chen style ( not even looking at the research in my own book which only looked at the Chen Yi Lu set), shows that the Chen Pao Chui sets were lost by the time Yang Lu Chan was learning at Chen village.
If it ORIGINALLY was derived from Shaolin Pao Quan (which was part of Shaolin Hong Quan system, which was part of Taoist Dong's Tong Bei system that was taught to the early Chen family and Li family founders of the Chen style), it was lost by Yang's time.
According to Peter Lim's site:
The Chen Family Cannon Pounding Art (Pao Chui)
The Chen family assimilated all the arts they practiced and created their own version of the predominant art which they practiced, Cannnon Pounding (Pao Chui), derived from the original Shaolin Cannon Pounding art. Sung Tai Zhu Chang Chuan formed a major part of this new art and there were elements from Shaolin Red Fist in it.
What resulted is five routines of Chen family Pao Chui and one routine of `Short Hitting' (duan da) and the song formula stated a total of a 108 postures consisting the art. There is much confusion over this particular song formula but on closer examination the correct name should be 'Boxing Canon Complete Formula' and is only found in the later Liang Yi Tang Ben manual. By the time the Wen Xiu Tang Ben Chen family martial arts manual was written it was noted that the `second and third routines are lost'. The Wen Xiu Tang Ben makes no reference to an art called Taijiquan or '13 postures' or 13 anything for that matter. So it is an early reference to the state of the Chen family arts before the advent of the Taijiquan of the Chen family that we know today.
The Chen family was famous for the Cannon Pounding art for several generations and gained the beautiful name of `Cannon Pounding Chen Family' (Pao Chui Chen Jia) in the region around the Chen village.
The Simplification Of Chen Routines
Somewhere along the line the Chen Pao Chui art was simplified to just two routines. We have no evidence to indicated who was the one responsible for this simplification. The furthest that we can trace it back is to Chen Chang Xin, Yang Lu Chan's teacher. But even the Chen family genealogy book does not indicate that he was responsible for this momentous change, only indicating that he was a boxing teacher with a nickname `Ancestral Tablet'.
We know for certain that two of the routines were already lost by that time and so only the 3 remaining could account for the final two routines. Whether there was an integration or that another routine was lost through time resulting in the final two is not certain at all.
2. The 'final two" being the Chen Yi Lu and Er Lu sets.
So, the Pao Chui Er Lu has to be rebuilt.
And it certainly wasn't rebuilt from the Henan Shaolin Pao Quan sets that they have been practicing for hundreds of years. It's nothing at all like it. The Shaolin Pao Quan does not have Split, Tear, Shoulder, Elbow, at all (only their much older Louhan 13 Postures Qigong set has that). They don't match at all. The Chen Yi Lu sets very much match the Shaolin Hong Quan, Tai Zhu Chang Quan, and Rou Quan sets very closely. So why wouldn't the Chen Pao Chui set match the famous and hundreds of years old Shaolin Pao Quan sets?
Yang Lu Chan wasn't taught Chen Pao Chui by Chen Chang Xing (1771–1853) because it wasn't there.
3. If anything, the Pao Chui Er Lu set may have been created by Chen Chang Xing's contemporary, Chen Youben (陳有本; 1780~1858), also of the 14th Chen generation,
But from what?
And the small frame went to Zhao Bao village,through Chen Qingping (陳清平 1795–1868) WHICH HAS NO PAO CHUI SET.
(So, how does Li Yiyu, who was the nephew and successor of Wu Yuxiang creator of the Wu style, and Wu is said to have studied for ONLY a FEW MONTHS in Zhao Bao,
and thereafter taking 20 years Wu and Li to develop their Wu style - which a Small frame looking Pao Chui form is attributed on Youtube to LiYu, but what is the actual lineage? Is it authentic?) BUT Zhao Bao doesn't have Pao Chui, which means Chen Qingping didn't teach it?
4. AND NO ONE ever outside of Chen village, besides Yang Lu Chan, ever saw Chen TJQ until 1928,when Chen Zhaopei (1893–1972) and later his uncle, Chen Fake (1887–1957) moved from Chen village to teach in Beijing. And people saw that the Chen style was radically different from the Yang and Wu and Wu/Hao styles.
5. In Taiwan, Du's style of Chen TJQ is from Chen Yan Xi, Chen Fake's father, we have all seen it's Yi Lu set, but they have No Pao Chui?
6. Why did old timer Chen Qing Zhou whose teacher was Chen Zho-Pei learn Pao Chui from him and not from others in his village?
Why did the rest of the well known Chen TJQ people who studied Chen style in their village since youth later learn Pao Chui from Chen Zhao Pei, once he was sent back to the village to cultivate a group of stars?
See? Lots of questions of the Chen Pao Chui set that we see TODAY.