Unfortunately, there is no information about the integration of G’MIC with GEGL (offering direct preview on canvas).
On GimpChat (How to write python plugin preview? - Page 2 • GIMP Chat), Tin Tran (author of the now defunct GimpLearn website) presented a number of plugins offering the ability to preview live on canvas using gtk2.
Unfortunately, we lack a person who knows gtk well.
Tin Tran uses ChatGPT and I use trial and error.
If anyone sees any sense in this and could help optimize the code, please support the development of the plugin.
As if in spite of G’MIC’s lack of connections with GEGL: