Puzzling Evidence - Another Example of the Mysterious Tian He 天合 Mark on Chinese Cloisonne

A previous post discussed the mysterious Tian He 天合  workshop and its distinctive products:

eBay vendor dead-guy-stuff found a dragon vase from this workshop:

The vase displays a "CHINA" country of origin stamp as well, the use of which seems to have stopped in 1950 when the twenty years of the China trade embargo by the United States began.

This "CHINA" export stamp on this vase seems to be evidence that these products were prior to 1950.  But when?  1910s? 1920s? 1930s? 1940s?  The exuberant  dragons are skillfully depicted in what seems to be an effort to achieve a breezy, modern style, and the three-dragon composition appears on other Deco-era vases.  The amber overglaze  over white, seen at the top ruyi and bottom waves motifs, also seems to be something that gained popularity in the 1920s-40s.   The "peaked spiral" background diaper is neatly applied but not obsessively machine-like.  The rim is frequently seen in vases from the 1930-40s.

Who? When? Where?  Puzzling evidence...