doesn't really work !
as a test i start opera with a single window and there are four zygote starting by themselves. then there are some other with gpu rendering etc.
It appears that the "tunables" shown in settings are "cosmetic" and serve the purpose of "eliding the UI" component but not the functionality and/or backend instances.
Anyways, i dont think the problems of opera are going to get fixed until it is released as "free software" !
Thanks for your time.