Maybe this question is non-sense. If I have a commom 12V relay (12V, 400 ohms coil) WITHOUT having a flyback diode connected to it, and driven by a low-side protected transistor/IC like ZXMS6004FF (the internal over-voltage protection would do the diode job). The datasheet of the transistor shows it withstands to a 90mJ "Unclamped Single Pulse Inductive Energy".
This is for a very specific project question. Would the transistor get damaged?
Datasheet of ZXMS6004FF: https://www.diodes.com/assets/Datasheets/ZXMS6004FF.pdf