[Question/Feature] Hooking ROM source directly

Hi guys,

Thank you for your great work. I've successfully tested and used EdXposed on my phone, especially with XPrivacyLua and FakeGApps.
I've been recently building my phone's ROM myself (using phh's GSI patches on top of AOSP and, more recently, Lineage sources) and I was wondering if it is possible to patch the sources with hooks directly, so that I could use Xposed modules without needing to do the Riru voodoo around zygote? I believe this would make EdXposed more stable and, possibly even stealthier (for SafetyNet purposes), if implemented with that in mind.
To do this, where in the source tree should I start digging? I suppose I should expose an interface similar to YAHFA/SandHook (where is that interface defined?) and rewrite the upper bits of EdXposed (where are those?) to link XposedBridge with the rom builtin implementation. I've read the wiki here and poked a bit through the tree, but it wasn't very illuminating.

I think #532 and #725 might also be relevant.