I don't understand what that whole fuss about blocking PBN backlinks for Ahref and Majestic is about, given that:
1) Nobody is going to be interested in your backlink profile except competitive SEO practitioners (and Google)
2) Those guys (like us) can't be fooled anyway, because you find backlinks that the tools don't show but that are indexed by google easily on Google itself.
Yes, it's an additional manual step, but if you're that deep into analysing competition, a small step for you.
Maybe someone more advanced can shine some light on it, why it's still done?