@xavier60
Can you please answer a few questions about your PSU ?
1. Can R32 and R33 be omitted ?
2. What type of diodes are D2, D3 and D10 ? 1N4148 ?
3. C9 is polarized ?
4. Where should be connected the shutdown K of the diode ?
5. It is good to build this PSU ?
R32 is a 100mA polyswitch and isn't important if there is no concern about the regulator breaking down.
R33 is a 100mA polyswitch which protects the preload circuit from reverse polarity. The whole preload circuit can be replace by a resistor.
Diodes D2, D3 and D10 can be 1N4148.
C9 can be a polarized electrolytic capacitor. I like to use leaded monolithic ceramic capacitors.
Shorting the shutdown K of the diode to ground turns off the regulator's output.
My design and the one imo is developing are very similar. You should stay with that design with some changes.
The under voltage lockout idea with D9 should work well. It might not need D6 and R16. The gain of Q1 is easy to change by changing the value of R25 if necessary.
My design does not have a reliable under voltage lockout to suit other op-amp types.
The CC buffer can go and there is no need for the op-amp for the CC LED, just copy what I have done.
Ill stop at this point. Draw up a new circuit, then we will sort out more details.
R23 and R24 are 10K 10 turn pots.