I’m also banging my head and I can’t find any effective solutions, I tried with the panel ID but after restarting the PC it doesn’t work anymore, Is your code stable and does it open the chosen panel even after restarting the PC?
It’s even easier to put the name of the panel to open it.
Also found a more reliable method for doing this since the secondary panel must be triggered from the main panel, you have to find it in the array of panels and it’s not always the last one so .pop() doesn’t work all the time:
It’s reliable until Adobe decides to change the uxp.entrypoints._pluginInfo. Any property starting in underscore is internal and should not be used by 3rd party. Most likely it’s here to stay, but you’ve been warned I think I use it too in one of my plugins