OpenCL is completely disabled and unavailable in GIMP-CCE for reasons given in Section E1 #6 of this page: https://ninedegreesbelow.com/photography/patched-gimp-compared-to-default-gimp.html
Regarding the splash screen, my apologies, I haven’t updated the splash screen since 2.9.4 was released and GIMP rolled over to 2.9.5. The splash screen has no bearing on functionality and I never thought to ask anyone to make an updated splash screen when 2.9.6 was released upstream and GIMP rolled over to 2.9.7.
The GIMP CCE code is up-to-date with upstream default babl/GEGL/GIMP code through October 1, 2017, which is to say, the version is 2.9.7. My web page on building CCE is somewhat out of date wrt to when I last uploaded new code.
I’m not sure what you mean by “into System Resource”.