Poison Pathfinder is severely lacking damage after 1st ascendancy

While the spreading poison idea is extremely cool and satisfying and it's part of the reason why I have so many hours in PoE 1, it doesn't really hit the mark in PoE 2. We don't really need clear speed options so early in the game, bossing could be so much more exciting if we had more active damage scaling options than just shock. Also, withering is almost impossible to apply early, as withering touch requires chaos damage hits and Cultist Bows have terrible damage scaling for poison (physical damage rolls don't affect the final chaos damage roll).

Problem:

Pathfinder's missing interesting single target damage options after 1st ascendancy. Withering touch too difficult to apply during these levels.

Solution:

Give Contagious Contamination a small amount of physical damage converted to chaos.

This isn't a large damage buff directly, but it would facilitate withering touch application prior to level 50 (when I assume we start finding level 3 supports).