Meep 6244 has three options for their Deadly Vampire Bites mod, one is completely custom and two are overrides of the existing in-game drink deeply and drink uncontrollably files that have been tweaked to be made fatal.
None of those conflict with A Reason to Slay - the main module of my mod uses custom interactions for NPC vampires drinking autonomously and drinking during a vampire invasion. The optional crosspack doesn't override any of those files, either. You won't have deadly NPC vampires running around autonomously biting people, is all.