existing CSAM and providing it under controlled conditions

This would go directly against the needs of the victims.

I was able to find an organisation which helps pedophiles and also conducts anonymous surveys. The pedophiles themselves reported they feel addicted to CSAM, most have come first in contact when they were minors themselves and nearly half want to seek contact to children after watching CSAM.

Survey of German pedophiles

Survey of Russian pedophiles

Research about the surveys