Hello,
Based on article: https://www.analog.com/en/resources/technical-articles/ideal-diode-combines-200v-busses.html

Can depletion mode Q3 be replaced by JFET? Both exhibit normally-on characteristic and turn off at negative VGS. D3 would need to be adjusted for the more negative Vth of JFET.
Let me know, thank you,
-Orlando