I haven’t seen this documented anywhere but I found out that in order to allow Jerboa to actually use private tabs when opening external links, you need to manually enable 2 Chrome flags:

chrome://flags/#cct-incognito
chrome://flags/#cct-incognito-available-to-third-party

basically enter these urls in chrome, and click on “Enable” and restart your chrome, and you should be back to care-free NSFW link browsing in no time

by the way, this worked on my Samsung s22 Android phone, haven’t really tried anything else…