Scaling runes, do they count as base or bonus stats?

I'm asking for a number of reasons. Right now I'm making a runepage for cinderhulk junglers and I'm wondering if getting seals of scaling health will contribute to the 25% bonus health modifier from cinderhulk or if it will still count as base stats like flat runes do.

Theoretically, with all of the base regen changes, this would be really powerful if they still counted as base stats. Imagine not having to build Tear on Cassiopeia because you have seals of scaling mana regen and base mana regen modifiers (Morellonomicon, Athene's). Or imagine scaling health regen seals on Mundo along with the plethora of base health regen items that are in the game right now. These champions would be absolutely broken late game.