I reported the missing get-task-allow entitlement to Apple’s code-level support, along with some backstory. They told me to report via Feedback Assistant, which I did a little less than 2 months ago.
And…good news, I got a ping on the report implying it might be fixed on the latest macOS 26 beta 4. I can confirm — the entitlement is present on the binary and I can attach a debugger directly (without disabling SIP).
Hope it sticks this time around!