I think I got it. No opto-frying with this setup.
Plus only one resistor for the 3 LEDs and one one 1,5k resistor for the opto.
I’m willing to risk the reverse breakdown voltage of the LEDs. However the opto is more important. I f the LEDs fail is not a big deal.
Thank you for the charlieplexing suggestion. With this setup there’s only one alternate path with two LEDs, namely
+++ LED1 >>> LED3 ----- (no resistor)
+++ TLP222G >>> R1K5 ------
If I understand correctly, in a charlieplexing setup current will not flow across alternate paths.
However, will this also be true if the alternate path has no resistors present?