Avalanche Diodes as EHT Stabilisation

[ppppenguin]

AFAIK all PN junction diodes exhibit avalanche breakdown. The unknowns are around how well controlled it is and what level of current it can stand before damaging the device. The zener effect appears similar but is a different phenomenon. Zener breakdown is typically below 5V.

https://en.wikipedia.org/wiki/Zener_effect

This article claims that avalanche breakdown has hysteresis, rather like in neon bulbs. There is no citation for the claim
https://en.wikipedia.org/wiki/Avalanche_breakdown