Hey cyberenchanter! I'm sorry this doesn't answer your question, but how did you manage to compile Graphene with Kernelsu? Is there a guide to follow that I couldn't find? Many thanks!
Also, maybe this could be helpful: 1 I would ask this question elsewhere. Users of this forum usually have the mentality that root is a security issue, not a feature. To each their owns IMO. I would instead try on pixincreate, chenxiaolong or cawilliamson's Githubs or on XDA. They are meaning to solve this.
2 Unfortunately, you know more than I do regarding this, but if I may suggest, the root community on reddit seems to have a few success stories. I would check there see if you could translate the mix of right modules on Graphene